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Introducción: el adenoma pleomorfo es la neoplasia de mayor incidencia de glándulas salivales, representando alrededor del 3-10 % de los tumores de la región de cabeza. La lesión linfoepitelial benigna por otra parte ha sido ampliamente reconocida como una causa común de agrandamiento de la glándula parótida en pacientes por lo general infectados con VIH. Las lesiones quísticas de la glándula parótida son poco frecuentes, se caracterizan por ser tumores de crecimiento lento, asintomático, de consistencia firme y cubiertos por piel o mucosa sana. Objetivo: describir las características histológicas, clínicas e imagenológicas, las cuales han de llevarse a cabo de manera multidisciplinaria, para realizar un plan de tratamiento adecuado y acertado de la patología. Caso clínico: paciente masculino que asiste a consulta por presentar lesión tumoral asintomática, ubicada en región preauricular derecha. Se envía resonancia magnética de la zona confirmando la lesión, se realiza abordaje quirúrgico para eliminación de la lesión y tejidos comprometidos. Posteriormente, estudio histológico confirma el diagnóstico de adenoma pleomorfo. Conclusión: Aunque la intervención quirúrgica es el tratamiento de elección tanto del adenoma pleomorfo como de la lesión linfoepitelial benigna, se hace imperativo realizar un exhaustivo estudio clínico, imagenológico e histopatológico de la posible lesión, y así descartar otras entidades que requieran un plan de tratamiento totalmente distinto, y así evitar cometer errores.

Sussex Archaeological Collections, 158, 107-119, This paper presents the results of recent research into the manor of Alciston, particularly the manorial buildings during the 14th century. Contemporary descriptions of the manorial buildings are placed in the context of the agricultural landscape and village. Observations of the current landscape and standing structures have helped to inform this study. This analysis reveals how the manorial curia may have appeared to a visitor in the later Middle Ages. It shows how construction material was used to draw the viewer's attention towards certain buildings. It also shows that the courtyard was organised to optimise farming practices, rather than as a display of lordly power. Alciston was one of the most important manors in the Battle Abbey estate and was regularly visited by the abbot. Studying the buildings of its curia provides new insights into life in medieval Sussex.

During Late Paleocene–Early Eocene times, the modern Rosebank structure was located at the juxtaposition of the easterly advancing Flett volcanic system and the northerly prograding Flett delta. As a result, the Rosebank reservoir sandstones are interstratified with volcanic and volcaniclastic rocks, offering challenges for reservoir imaging, depth prediction and reservoir characterization. These challenges have driven the application of Ocean Bottom Node (OBN) seismic technology. OBN data have yielded improved velocity models for depth conversion, better reservoir definition and key insights to aid the modelling of sand distribution from seismic attributes. Spectral decomposition of the OBN seismic data has facilitated the extraction of distinct volcanic subunits, whilst spectral enhancement has enabled visualization of complex stacking patterns within individual igneous layers. To complement the seismic analysis, detailed geological analogue studies have been undertaken in volcanic provinces such as the Palaeogene volcanic district of SE Greenland and the Columbia River Flood Basalt Province, USA. No single outcrop provides a definitive analogy to Rosebank, but each offers insights that provide an important link to understanding and managing the main subsurface uncertainties associated with field development. Integration of these multiple workflows have improved the reservoir characterization and provided the foundation for the optimization of the field development plan.

During processing of ready-to-eat (RTE) deli meats, any secondary processing procedures such as peeling and cutting introduce the distinct possibility of cross-contamination between equipment, personnel, and food. To eliminate or reduce pathogens such as Listeria monocytogenes and ensure food safety, RTE deli meats can be pasteurized prior to or after packaging. In this study, ambient steam in-package pasteurization was compared with pressurized steam prepackaging pasteurization to reduce L. monocytogenes from fully cooked RTE bologna. The bologna (14 cm diameter×1.5 cm thickness) samples were surface-inoculated to contain about 8 log 10 of L. monocytogenes . To achieve 2 log reductions for L. monocytogenes , the bologna samples needed to be treated for about 10 s in pressurized steam at 131 °C or for about 2.5 min in ambient steam at 100 °C. The pasteurization time using pressurized steam treatment was about 75–90% shorter than using ambient steam treatment. Pressurized steam treatment may be integrated into a vacuum packaging unit to effectively eradicate L. monocytogenes from RTE meats just prior to sealing the retail packages to further reduce the treatment time, avoid post-treatment recontaminations by pathogens, and improve food safety without detrimentally affecting meat quality.

Chicken leg quarters (180–230 g) were processed for 4 min in steam at 99°C and then in an air impingement oven for 24 min at an oven temperature of 232°C, an air velocity of 2 m/s, and a humidity of 60%. The cooked chicken leg quarters were sampled to measure for the end-point internal temperatures. Sampling size in each subgroup for the internal temperature measurements was determined based on a normal distribution at a confidence level of 95%. The process mean, range, and standard deviation at 95% confidence level were 73.9°C, 1.8°C, and 0.9°C, respectively, for the internal temperatures of the cooked chicken leg quarters. The process lethality was validated for up to 7 log 10 cfu/g reductions of Listeria monocytogenes in the cooked chicken leg quarters and verified by an inoculation study in which the chicken leg quarters were injected with 0.1 ml of the culture per cm 2 of the product surface area to contain 7–8 log 10 cfu/g of L . monocytogenes . This paper provided an approach for process control, sampling, and validation to reduce pathogens in fully cooked poultry products.

Thermal inactivation D and z values of Salmonella and Listeria monocytogenes were obtained for chicken thigh and leg meat and skin. The D values of Salmonella at 55 to 70 degrees C were 43.33 to 0.07 min in the meat and 43.76 to 0.09 min in the skin. The D values of L. monocytogenes at 55 to 70 degrees C were 38.94 to 0.04 min in the meat and 34.05 to 0.05 min in the skin. The z value of Salmonella was 5.34 degrees C in the meat and 5.56 degrees C in the skin. The z value of L. monocytogenes was 5.08 degrees C in the meat and 5.27 degrees C in the skin. For Salmonella or L. monocytogenes, the z value of the meat was not different from that of skin. However, the z value of Salmonella in meat or skin was different from that of L. monocytogenes in meat or skin. The z value of Salmonella or L. monocytogenes in chicken thigh and leg meat was different from that in the skin. The results from this study are useful for predicting process lethality of Salmonella and L. monocytogenes in products that contain chicken thigh and leg meat or skin.

Thermal inactivation of Escherichia coli O157:H7, Salmonella, and Listeria monocytogenes in ground pork was compared. The D (decimal reduction time at a certain heating temperature) values of E. coli O157:H7, Salmonella, and L. monocytogenes at 55 to 70°C were 33.44 to 0.048 min, 45.87 to 0.083 min, and 47.17 to 0.085 min, respectively. The z (temperature rise for 1 log10 reduction of D) value of E. coli O157:H7, Salmonella, and L. monocytogenes in ground pork was 4.94°C, 5.89°C, and 5.92°C, respectively. Significant difference was found on the D and z values between E. coli O157:H7 and Salmonella or between E. coli O157:H7 and L. monocytogenes. The D and z values of Salmonella in ground pork were not significantly different from L. monocytogenes.

Chicken leg quarters were injected with 0.1 ml of the cocktail culture per cm2 of the product surface area to contain about 7 log(CFU/g) of Salmonella. The inoculated leg quarters were processed in an air/steam impingement oven at an air temperature of 232 degrees C, an air velocity of 1.4 m/s, and a relative humidity of 43%. The endpoint product temperatures were correlated with the cooking times. A model was developed for pathogen thermal lethality up to 7 log(CFU/g) reductions of Salmonella in correlation to the product mass (140 to 540 g) and cooking time (5 to 35 min). The results from this study are useful for validating thermal lethality of pathogens in poultry products that are cooked via impingement ovens.

The D and z values of Salmonella, Listeria innocua, and Listeria monocytogenes were obtained for different ready-to-eat poultry products, including chicken, turkey, and duck. The D values of Salmonella, L. innocua, and L. monocytogenes were 151.5 to 0.1 min at 55 to 70°C, and the z values of Salmonella, L. innocua, and L. monocytogenes were 4.9 to 7.0 °C. Significant differences were found for the heat resistance of Salmonella, L. innocua, and L. monocytogenes among turkey, duck, and chicken products, indicating that the kinetic values of a certain pathogen in a specific product should be used for determining process lethality in fully cooked and vacuum-packaged poultry products during post-cook heat treatments.

Fully cooked chicken breast fillets and strips were surface inoculated with a cocktail of Listeria monocytogenes culture. The inoculation level was 10(7) to 10(8) CFU/g meat. The inoculated products were vacuum packaged and pasteurized at 90 degrees C with a pilot-scale steam or hot water cooker. After heat treatment, the survivors of L. monocytogenes were enumerated. No significant difference was found on survivors of L. monocytogenes between steam- and hot water-treated products. To achieve a 7-log10 (CFU/g) reduction, approximately 5, 25, and 35 min were needed for single-packaged fillets, 227-g package strips, and 454-g strips, respectively. The results from this study were subsequently verified by a computer model that could predict the thermal lethality of pathogens in fully cooked meat and poultry products during postcook in-package pasteurization.

The study was conducted to determine the effect of packaging-film thicknesses on thermal inactivation of Salmonella and Listeria innocua in cooked chicken breast meat. The meat was inoculated to contain 107 CFU/g of Salmonella or L. innocua and vacuum-packaged in a thickness of 0.0762- or 0.2032-mm film. The packaged meat was heat-treated in a water bath at 68°C for 10 to 120 s and then cooled in an ice-water bath. The survivors of Salmonella or L. innocua were enumerated. This study revealed that packaging-film thicknesses affected thermal inactivation of Salmonella and L. innocua. The results are useful for surface pasteurization of fully cooked and vacuum-packaged meat and poultry products.

Studies were conducted to determine thermal inactivation D- and z-values of Salmonella and Listeria innocua in fully cooked and vacuum-packaged chicken breast meat. Fully cooked chicken breast meat products that were obtained from three different sources with differing formulations were uniformly inoculated with a cocktail of Salmonella (including Senftenberg, Typhimurium, Heidelberg, Mission, Montevideo, and California) or L. innocua at approximately 10(7) cfu/g. The inoculated meat samples were vacuum-packaged and then heat-treated at a temperature of 55 to 70 C for 5 to 90 min. After heat treatment, the samples were immediately cooled in an ice-water bath. Survivors of Salmonella and L. innocua were enumerated for each sample. D- and z-values of Salmonella and L. innocua were determined for each product and compared among the products. Source and formulation did not cause significant differences in the D- and z-values of Salmonella or L. innocua among the three fully cooked and vacuum-packaged chicken breast meat products.

Beef/turkey blended patties, containing 107 to 108 cfu/g of Salmonella Senftenberg or Listeria innocua, were battered and breaded. The effect of frying (177 °C) and air convection cooking (288 °C) on thermal inactivation of S. Senftenberg and L. innocua was evaluated. A model was obtained to correlate product internal temperature with frying and oven cooking time. Cooking method significantly affected thermal history and subsequently the thermal inactivation of S. Senftenberg and L. innocua. The effect of frying time interacted with oven cooking time. Increasing frying time reduced the oven cooking time. Mathematical models were developed to correlate the survival rate of S. Senftenberg or L. innocua with frying and oven cooking time.

Fully cooked chicken breast strips were surface inoculated to contain 9 log 10 (CFU/g) Salmonella Senftenberg or Listeria innocua. The inoculated products were vacuum packaged in 0.2-mm-thick harrier bags (241 by 114 mm), then steam pasteurized at 88°C in a continuous process for 26 to 40 min or in a hatch process for 33 to 41 min, After the treatments, the products were analyzed for the survivors of Salmonella or Listeria. The models were developed to correlate the surviving rate of Salmonella and Listeria with cooking time for both continuous and batch processes. A cooking time of 34 min was needed to achieve 7 logs of the reduction in a batch process. To achieve the same log reduction, a longer (6 min) cooking time was needed in a batch process than in a continuous process, The results from this study will he useful for processors to evaluate postcooking treatment procedures for ready-to-eat meat products. Du poulet cuit est inocule avec Salmonella senftenberg ou Listeria innocua, puis emballe sous vide et traite a la vapeur en vue de la pasteurisation. Une analyse microbiologique est menee apres le traitement. La survie des bacteries est modelisee, en fonction du temps de cuisson. Une cuisson de 34 minutes est necessaire pour qu'une reduction de 7log ait lieu lors de la pasteurisation en discontinu.

Ground chicken breast patties were inoculated, throughout, to contain 107 cfu/g of Salmonella Senftenberg or Listeria innocua. The inoculated products were cooked in a single layer or double overlaps in a pilot-scale air/steam impingement oven following storage in an equilibrium chamber that maintained the air at dewpoint. The cooking oven was maintained at 232°C, air circulation of 13 m3/min, and air moisture of 60% (vol/vol). The total dwell (cooking) time was 3.5 to 5.0 min, including a dwell time of 1.0 min in the equilibrium chamber. The endpoint temperature in singlelayered patties ranged from 53 to 68°C. The temperature between the overlapping surfaces was about 50% less than that at the center of single-layered patties. After being cooked, the Salmonella or Listeria population in the products was enumerated and compared among the patties that were cooked as a single layer and as overlaps. Salmonella and Listeria in the overlapped patties were about 6 logs more than that in the products that were cooked in a single layer. This information is useful for evaluating and controlling commercial meat cooking processes.

Salmonella spp. or Listeria innocua containing chicken patties were processed via a pilot-scale air-convection oven to a final temperature of 55 to 80 8C. Thermal processing was conducted at an air temperature of149 8C, an air velocity of 7.1 to 12.7 m 3 /min, and a wet bulb temperature of 39 to 98 8C. The cooking time wascorrelated with cooking conditions using a standardized least square regression model. The models were developedto correlate cooking time and the thermal inactivation of Salmonella or Listeria with cooking conditions. Thethermal lethality of Salmonella and Listeria increased with increasing product temperature and wet bulb tempera-ture. This study bridged the gap between laboratory studies and commercial applications and will help commercialprocessors to evaluate and validate their thermal processes.Key Words: poultry, Salmonella , Listeria , lethality, convection cooking Introduction T HE MARKET FOR READY - TO - EAT POUL -try products has experienced tre-mendous growth in recent years, with avariety of patties, nuggets, strips,breasts, thighs, and wings being avail-able to the consumer through retailingand catering. This tremendous growthhas led to serious concerns over thesafety of the products due to the pres-ence of pathogens, and an emphasishas been placed on the thorough cook-ing of the meat products. The USDA-FSIS current regulations require thatthe processor provide the supportinginformation for the hazard analysis anddecision-making documents associatedwith the development of HACCP plans,critical limits, selection and frequencyof monitoring, and verification proce-dures (USDA-FSIS 1999). According tothe current regulation, there are nostandard operating procedures for sci-entific and/or correlation studies. It isthe processor’s responsibility to providethe in-plant data for the scientific sup-port and to demonstrate that the estab-lishment is able to meet the parametersoutlined in the HACCP plans for theiroperation. This study aimed at evaluat-ing commercial operating conditionsand supplying useful information tocommercial processors and regulatoryagencies for the pathogen lethality vali-dations of commercial thermal pro-cesses.Previous studies indicated that manyfactors affected the pathogen thermalinactivation. Pathogen thermal inactiva-tion kinetics was different between liq-uid medium and meat substrate (Mur-phy and others 2000b). It is known thatthe laboratory evaluation of thermal in-activation of pathogens is influenced bya number of factors including tempera-ture, the pathogen strain and its history,the meat species (or medium types)and its composition, and a number ofenvironmental factors such as pH, wa-ter activity, and chemical additives(Ghazala and others 1995; Heddlesonand others 1994; Huang and others1993; Kim and others 1995; Murphy andothers 1999; Patchett and others 1996;Veeramuthu and others 1998). Inactiva-tion kinetics have been obtained for

The Erris Trough is a narrow, elongate, Mesozoic basin lying adjacent to the eastern margin of the Rockall Trough to the northwest of Ireland. Limited drilling in the area has proven Carboniferous, Permo-Triassic, Lower–Middle Jurassic and Cretaceous sediments beneath a thin Tertiary cover. Considerable variation in structural style and preserved stratigraphy is observed along the basin. Based on interpreted fault polarity and observed pre-Cretaceous stratal dip, the Erris Trough can be subdivided into three structural sub-basins separated by diffuse, poorly defined, overlapping or divergent transfer zones. Carboniferous basin development in the area of the Erris Trough was significant but is poorly constrained. Permo-Triassic rifting produced a series of half-graben, some of which were controlled by down-to-the-southeast faults. This extensional phase was followed by post-rift subsidence during the Early and Middle Jurassic. In addition, N–S and NW–SE faults locally influenced depositional patterns. In the southern part of the Erris Trough a Middle to Late Jurassic rifting event produced a reversal of the earlier basin geometry with the generation of northwest- and west-downthrowing normal faults. Along the western margin of the Erris Trough, footwall uplift associated with this event induced massive, kilometre scale, uplift and erosion implying Late Jurassic rifting within the Rockall Trough. Restricted basins may have been developed in the area during the Cretaceous as a result of ‘ponding’ of deposition to the east of this zone of footwall uplift. A minor extensional phase occurred during the Aptian–Albian resulting in local reactivation of the Late Jurassic faults concurrent with rifting in the Rockall Trough. A westerly tilt of the basin was established during the Late Cretaceous–Early Tertiary caused by downflexing associated with thermal subsidence of the Rockall Trough. Regional uplift and erosion occurred during the Oligocene–Miocene. Basin modelling indicates that Lower Jurassic source rocks may have generated oil during the Early Eocene to Early Miocene, dependent on an elevated geothermal gradient during the Early Tertiary. Late Carboniferous sediments may have generated hydrocarbons at a number of times during the basin’s history.

In eating skills programs, the tendency is to address the presenting physical problems by providing therapy or equipment to enable the patient to bring food to the mouth, chew, and swallow independently. To aid in more comprehensive treatment planning, ten categories of mealtime activities are described. Empahasis is placed on individualization of treatment by considering personal lifestyles and preferences. An interdisciplinary approach is described, as well as the importance of involving families.

Background: The addition of droperidol to morphine for patient-controlled analgesia reduces the incidence of nausea and vomiting, but may result in unwanted side effects. Method: We studied 40 women randomised to receive morphine sulphate with or without added droperidol (10mg droperidol/60mg morphine) by patient-controlled analgesia following elective caesarean section under spinal anaesthesia. Results: Median morphine demand in the 20h after surgery was 74mg with morphine alone, and 53mg with added droperidol, the median consumption of which was 8.8mg. The incidence of nausea was reduced from 80% to 38.8% (P

Experiments were conducted in a 6-yr-old citrus orchard to test the efficacy of different formulations of the nematodes Steinernema riobravis (Cabanillas,Poinar & Raulston) and Heterorhabditis baderiophora (Poinar) against a citrus root weevil, Diaprepes abbreviatus (L.), and to measure nematode persistence at different soil depths. One hour after application, >55% of both nematode species that were recovered in soil samples were at a depth of 0–1 cm and 33%of both species were recovered between depths of 3 and 15 cm. Numbers of S. riobravis at depths of 3–15 cm remained constant during the following 7 d, but numbers of H. bacteriophora declined 64%. During the same period, the numbers of both species recovered from depths of 0–1 cm declined by >99%. The data suggest that the lack of persistence reported for these nematodes in Florida citrus orchards is related to their vertical distribution in soil following application. Nine weeks after application, the numbers of D. abbreviatus at soil depths of 0–45 cm were reduced by 77 and 90%, respectively, in plots treated with liquid or granular formulations of S. riobravis . Neither formulation of H. bacteriophora affected the population density of D. abbreviatus .

Cerebral oximetry was evaluated as a monitor of oxygenation during carotid endarterectomy in 22 patients. The oximeter was a reliable continuous monitor, identifying changes in cerebral oxygenation during episodes of hypotension and after arterial occlusion. Changes in oxygenation correlated well with the surgical assessment of backbleeding after arterial clamping, but less well with other methods which are used to make a decision on insertion of an arterial shunt. There was no correlation between internal carotid artery stump pressure and change in cerebral oxygenation after application of the arterial cross clamp. However, cerebral oxygenation correlated weakly with the change in middle cerebral artery velocity as measured by transcranial Doppler ultrasonography (r = 0.49, p < 0.02).

Most girls go through puberty with awareness of their sexuality and recognition of the physical changes but with little concern for the details such as onset or rate of progress. Some girls and most mothers are not eager for sexual maturity and recognition of delay is late, unless there are complicating features. Diagnosis of delay and its cause may require careful observation over several months and judicious selection of appropriate tests. It is important not to jump to conclusions which may be wrong. Identification of the occasional serious cause is important since harm may result from delay. Recognition of constitutional delay from long-term causes of hypogonadotrophic hypogonadism may be difficult and replacement treatment may be advisable to gain oestrogen benefits with deferment of final diagnosis. Where there is a fundamental defect of the ovaries or genital tract which will prevent fertility, the condition must be communicated with sensitivity but without ambiguity. Conditions which are reversible so far as pubertal development is concerned require accurate diagnosis and, usually, long-term management.

Bulk precipitation was monitored at five sampling sites across the Cascade mountains east and windward of the urban Puget Sound area January 1981 through July 1981. The volume weighted average pH over the collection period at the Cascade Crest (Snoqualmie Pass) was 4.71. Sulfate was the dominant anion. The average strong acid composition in terms of sulfate and nitrate over the five collector sites ranged from 57 to 62 equiv % sulfuric acid. The sulfate deposition for 1981 at the Cascade Crest is estimated to be 16.0 kg ha/sup -1/ year/sup -1/ of SO/sub 4/ (sea salt corrected). The strong acid content of the samples was observed to increase in the summer months. Twenty-nine watershed source lakes lying along the Cascade Crest 3-20 miles north of the precipitation collectors were sampled during the summer of 1981. All of the source lakes were found to be susceptible but not acid, with alkalinities ranging from 4 to 190 ..mu..equiv/L. (Median alkalinity was 57 ..mu..equiv/L.) The composition of the waters in terms of alkalinity and calcium concentration was similar to that of nonacidified waters of northwestern Norway and northwestern Ontario.

Estradiol 17 beta-hydroxysteroid dehydrogenase (17 beta HSD) mediates the interconversion of estrone and estradiol in endocrine-responsive tissues such as the breast. The control of 17 beta HSD expression by all-trans-retinoic acid (RA) in T47D breast cancer cells was examined using a specific 17 beta HSD complementary DNA probe. Two main 17 beta HSD messenger RNA (mRNA) transcripts of 2.2 and 1.3 kilobases (kb) were detected, of which only the 1.3-kb mRNA was regulated. RA increased expression of the 17 beta HSD 1.3-kb mRNA in a dose- and time-dependent manner, and the increased expression of this mRNA by RA was inhibited by a 10-fold excess of a RA antagonist Ro 41-5253. Insulin-like-growth factor-I, interleukin-1, and estradiol, previously shown to increase 17 beta HSD activity in breast cancer cells, had little effect on 17 beta HSD gene expression. To relate the effect of increased 17 beta HSD 1.3-kb mRNA expression to 17 beta HSD activity, the conversion of estrone to estradiol (reductive) and that of estradiol to estrone (oxidative) were measured in intact T47D cell monolayers. Whereas RA increased 17 beta HSD reductive activity, it had no effect on oxidative activity. The addition of excess NAD increased 17 beta HSD oxidative activity in control and RA-treated cells, but the addition of NADH had no effect on 17 beta HSD reductive activity. These results suggest that the increased expression of the 17 beta HSD 1.3-kb mRNA induced by RA is associated with an increase in 17 beta HSD reductive activity, but that endogenous cofactor levels may determine the direction in which this enzyme acts in T47D cells.

Prenatal diagnosis for glutathione synthase (EC 6.3.2.3) deficiency in two pregnancies of an at-risk couple was performed on amniotic fluid taken at 16 weeks' gestation. 5-Oxoproline (pyroglutamic acid) levels were 970 and 790 mumol/l compared with the normal mean value of 29 mumol/l (range 13-51 mumol/l). The pregnancies were terminated and the diagnosis in one case was subsequently confirmed by assay of glutathione synthase in cultured fetal fibroblasts. In the other, post-mortem tissue samples failed to grow.

A computer model simulating the formation of an artificially ionized layer in the atmosphere by a series of microwave pulses was developed and is presented. The approach utilizes possible opportunities offered by the existing Arecibo transmitter and antenna. A modified version of the kinetic theory of the breakdown of air by a powerful microwave emission was incorporated into a model of electromagnetic propagation through the atmosphere by a converging ionizing microwave pulse. This model takes into consideration radio wave self-action as well as absorption, and produces profiles of electron concentration formed in the atmosphere by both an isolated pulse and a series of pulses. Effects of varying the shape of the ionizing pulse are considered as well as the influence of the ambient electron concentration. Also, the dependence of the electron concentration on the energy and duration of the pulse is investigated. The possible increase in the rate of electron production is considered when using an intense pulse to initiate the breakdown followed by a series of pulses of lesser energy. The influence of the refraction of the microwave beam is estimated. The computer model presented shows that an AIL (Artificial Ionized Layer) of electrons reaching concentrations on the ordermore » of 10{sup 8} cm{sup {minus}3} Could be formed over a height range of 40--70 km, if the Arecibo antenna and radio facility were reconfigured so that it would be able to generate microwaves with f = 2.38 GHz and a power of approximately 1--4 MW. In addition, a pulse compressor would be used to form pulses with durations of approximately 0.1--0.15 {mu}s with a repetition frequency of 103 Hz.« less

Twenty-two women who wished to continue their pregnancies were interviewed several months after their first miscarriage. Levels of anxiety and depression showed an extremely high degree of variability. Cognitive processes in the form of a search for meaning, mastery and self-enhancement hypothesised to be important in adaptation to negative events were assessed. Having an explanation for the miscarriage and the experience leading to a general reappraisal of values were associated with lower levels of intrusive thoughts. A belief in a medical cause was linked to lower anxiety. Women believed that neither they themselves nor their doctors could exert much influence over the outcome of future pregnancies. Stronger belief in personal control was associated with higher anxiety levels. There is a need to consider not only the emotional consequences of miscarriage but also the cognitive mediators influencing such responses and although based upon a small sample this study initiates that process.

Post-manufacturing thermal treatments are commonly employed in the production of hip replacements to reduce shrinkage voids which can occur in cast components. Several studies have investigated the consequences of these treatments upon the alloy microstructure and tribological properties but none have determined if there are any biological ramifications. In this study the adsorption of proteins from foetal bovine serum (FBS) on three Co–Cr–Mo ASTM-F75 alloy samples with different metallurgical histories, has been studied as a function of protein concentration. Adsorption isotherms have been plotted using the surface concentration of nitrogen as a diagnostic of protein uptake as measured by X-ray photoelectron spectroscopy. The data was a good fit to the Langmuir adsorption isotherm up to the concentration at which critical protein saturation occurred. Differences in protein adsorption on each alloy have been observed. This suggests that development of the tissue/implant interface, although similar, may differ between as-cast (AC) and heat treated samples.

A statistically significant decrease in sulfate was observed in high elevation Cascade lakes during 1983 through 1988. The total decrease averaged 2.2 μeq L−1 in two slow-flush lakes and 4.2 μeq L−1 in three fast-flush lakes for 1983–1985 vs 1986–1988, respectively. Coincident with these changes in sulfate concentrations were a sharp decrease of SO2 emissions from the ASARCO smelter (100 km SE of the lakes), from 87 to 70 kt yr−1 during 1983–1984 to 12 in 1985, the year of its closure, and a gradual change in SO2 emissions from Mt. St. Helens, from 39 to 27 during 1983–1984 to 5 in 1988. The sharpest decreases occurred in non-marine sulfate in fast-flush lakes from 1984 to 1985 (about 2 μeq L−1) and in slow-flush lakes from 1985 to 1986 (1 μeq L−1, which point to the ASARCO closure as the sole cause. However, some of the more gradual decline in non-marine sulfate observed during 1983 through the 1988 sampling periods may have been due to a slow washout of sulfate enriched ash from the 1980 Mt. St. Helens' eruption. Sulfate concentrations in precipitation also declined significantly by about 2 μeq L−1, but changes in volume-weighted sulfate content were not significant. Lake alkalinity did not show a consistent increase in response to decreased sulfate. This was probably due to either watershed neutralization of acidic deposition or the greater variability in alkalinity measurements caused by small changes in acidic deposition making it difficult to detect changes.

Rime and snow samples were cocollected at a site in the Cascade mountains east and windward of the urban Puget Sound area January 1989 through March 1989. The rime samples on average were 1.8-4.5 times more concentrated than cocollected snow in nitrate, sulfate, and ammonium ion. The concentrations of nitrate and sulfate obtained over common snow and rime collection periods were related. For those paired collections, the snow to rime nitrate concentration ratio was greater than the snow to rime sulfate concentration ratio. The extent of riming varied dramatically with location

Plant roots were mechanically injured or subjected to nematode parasitism to test the model of host damage by two nematode species: y = m' + (l - m')c'z₁P₁₁z₂P₁₂ for y ≤ 1.0 and y = 1.0 for y > 1.0, where m' = m₁ + (m₂ - m₁) (1 - y₂)/[(1 - y₁) + (l - y₂)] and c' = (z₁-T₁ + z₂-T₂)/2. Damage functions for greenhouse-grown radish plants (cv. Cherry Belle) mechanically injured with small or large steel needles were used to predict growth of plants injured by both needles. Growth predictions accounted for 94%, 87%, and 82% of mean treatment variation in plant height, stem weight, and root weight, respectively. Cowpea (cv. California Blackeye No. 5) damage functions, based on preplant population levels of Meloidogyne incognita and M. javanica, were used to predict seed yield of plants concomitantly infected with various levels of each species. Single species damage functions and population growth curves indicated significant host resistance to M. incognita and significantly lower virulence of that species compared to M. javanica. Model predictions accounted for 88% of mean seed yield variation in two-species treatments. In a separate experiment, mean top weights of 30-day-old cowpea plants, nniformly inoculated with 20,000 M. javanica eggs, increased with increasing levels of concomitantly inoculated M. incognita eggs. It is speculated that competitive interactions between M. incognita and M. javanica mitigated host damage by the more virulent species.

Taylor's Power Law was fit to Tylenchulus semipenetrans population data obtained from individual trees in a survey of 50 Florida citrus orchards (geographic survey) and to data from individual trees within a single orchard collected at regular intervals for 2 years (temporal survey). No significant differences were detected between slope or intercept values when log variance was regressed against log mean for the geographic and temporal data sets. The geographic survey was divided into two subsets of data according to the perceived size of patches of T. semipenetrans. Subsets consisted of orchards which appeared to have numerous small patches of trees infected by the nematode (small patch) and orchards in which most of the trees were infected (large patch). The slope value for the orchards with smaller patches of nematodes was different (P/= 0.05) from that from large-patch orchards. Assuming mean nematode levels of 1,000 juveniles and males/100cm(3) soil, sample sizes (predicted standard error to mean ratio = 0.20) estimated from the relationships of variances to means were 12 trees in the geographic survey and 11 trees in the temporal. Omission of the small-patch data from the geographic survey resulted in a 17% reduction in optimum sample size. Sample size in sporadically infested orchards was estimated to be 69 trees. A data transformation of x(0.23) was calculated from parameters of Taylor's Power Law fit to the survey data.

Grapefruit trees on sour orange rootstock on the east coast of Florida were treated with 22.3 kg a.i./ha fenamiphos (broadcast equivalent) in 1.52-m bands extending from the dripline to beneath the canopy, in 1.52-m bands extending from the dripline toward the row middle, or left as untreated controls. During the course of the experiment, mean density of feeder roots and Tylenchulus semipenetrans in control plots was 3.8 and 5.8 times greater, respectively, in samples from beneath tree canopies than from 90 cm beyond the dripline on the top of beds. Population densities of T. semipenetrans in each zone (under canopy vs. row middle) were smallest when treatment occurred in that zone. Nematode levels beneath the canopy were 11% of control levels 19 weeks following treatment when fenamiphos was applied beneath the canopy and 52% of controls when treated at the dripline. The number of female T. semipenetrans per gram root weight was also reduced under the canopy by the under-canopy treatment. Fruit yield 5 months following nematicide application was not affected by treatment. Percentage change in yield between that harvest and a harvest 16 months after treatment was + 17% in the under-canopy treatment, - 1% in the dripline treatment, and - 17% in the untreated controls.

Alyceclover (Alysicarpus spp.) is an annual, high-quality leguminous forage, suitable for production under tropical and subtropical climates where the husbandry of conventional leguminous forages, Trifolium spp., is uneconomical. The damage potential and reproduction of Belonolairaus longicaudatus and Hoplolaimus galeatus on alyceclover were studied under greenhouse conditions, using sand and sandy clay loam soil materials, respectively. Both nematode species reproduced on alyceclover, but only B. longicaudatus was pathogenic. Symptoms of B. longicaudatus damage were suppression of shoot yield, limited root system, stunting, incipient wilting, and occasional seedling mortality. In one experiment, the threshold-damage density was three nematodes/100 cm(3) sand, whereas in the other experiment it was zero nematodes.

Sixteen mature Valencia orange trees on rough lemon rootstock were selected on the basis of approximately equal, naturally occurring populations of Tylenchulus semipenetrans in soil. In March, fruit 1 cm in diameter or less were removed from eight of the trees, which were kept free of fruit for 15 months. In July, 4 months after fruit removal, fibrous root (

A survey was initiated to determine the incidence of Belonolaimus spp. (sting nematodes) in citrus orchards in the central ridge region of Florida, following widespread damage by these nematodes to young trees replanted after freezing weather in 1989-90. Sting nematodes were detected in 50% of 210 samples and in 64% of 84 orchards surveyed. More orchards in Polk County were infested with sting nematodes (82%) than in counties to the north (36%) or south (48%). Principal component analysis of morphometric data separated six of seven sting nematode populations in northeastern Polk County from six populations in adjacent regions. Stylet:tail ratio for nematodes in northeastern Polk County tend to be > 1.0 and were ≪ 1.0 for all other populations. Patchiness of nematodes within an orchard was associated with stunted trees (23% smaller), reduced root mass density (25% lower), and low fruit yield (57% reduction). Soil texture did not vary among trees of different size in the orchard, but soil water potential between irrigation events was highest beneath small trees with low root mass density. Results of the survey indicate that the incidence of sting nematodes in orchards on the central ridge is much higher than previously estimated and that sting nematodes can cause substantial damage in replanted orchards. Further research is needed to evaluate the significance of sting nematode population variability and its relationship to citrus crop loss in Florida.

Population development of Tylenchulus semipenetrans in dry soil was investigated in a greenhouse study. Citrus seedlings were grown in sandy soil in vertical tubes with upper and lower sections. Nematode population densities in the upper tubes were measured at 16, 23, and 37 days, post-treatment. Three treatments consisted of i) irrigating both tubes when soil water potential reached -1 5 kPa (non-drought), ii) irrigating only the bottom tube (local drought), and iii) no irrigation (uniform drought). Soil water potential in the upper tubes did not differ under local and uniform drought during the first 16 days post-treatment, when it approached - 125 kPa. Thereafter, the water potential of soil under uniform drought continued to decrease, while that under local drought stabilized at approximately -150 kPa. Treatments had no consistent effects on female T. semipenetrans counts from soil or roots. However, after 37 days, numbers of eggs, juvenile, and male nematodes per gram of root under local drought were more than 2.4-fold greater than those under non-drought or uniform drought. Numbers of juvenile and male nematodes in soil were 6.5 times higher under local drought than under non-drought after 37 days. Nematodes did not survive in soil under uniform drought. Most of the eggs recovered on each date, from roots under local and non-drought, hatched within 35 days. Sixteen days of uniform drought reduced cumulative egg hatch to 51%, and almost no eggs hatched after 23 and 37 days of uniform drought. Thus, the response of T. semipenetrans to dry soil is fundamentally different, depending on whether all or part of the rhizosphere experiences drought. These data and field observations suggest that hydraulic lift via the root xylem may prolong the activity of some nematodes and possibly other rhizosphere-inhabiting organisms in dry soil.

Laboratory microcosms were used to: i) measure the effects of soil moisture on survival of Steinernema riobravis and ii) investigate the suitability of using microcosms to study motility and survival of these nematodes. Nematodes recovered from soil contained in petri dishes declined by more than 95% during 7 days, whereas nematodes recovered from the inner surfaces of dishes increased 35-fold. After 7 days in dishes, >20 times as many nematodes were recovered from dish surfaces than from soil. Nematodes exhibited a negative geotropism; greater numbers of nematodes were recovered from the lid surfaces than from the surfaces of dishes. Survivorship of nematodes in soil in plastic centrifuge tubes was somewhat greater than in petri dishes, and fewer nematodes ascended above the soil line in tubes than dishes. Downward migration of nematodes was inversely related to soil column diameter, possibly due to relatively unimpeded movement along container surfaces. An assay was developed by which nematodes were rinsed from the inner surfaces of centrifuge tubes into the soil. The resulting slurry was then processed on Baermann trays to recover motile nematodes. Nematode survival in soil in centrifuge tubes was higher at soil moistures between 2-4% than at lower (0.5-1.0%) and higher (4.0-12.0%) moisture levels. Survival of S. riobravis may be enhanced by quiescence induced by moisture deficits.

Citrus seedlings were grown in double pots that separated the root systems into discrete lower and upper zones to test the hypothesis that hydraulic lift affects persistence and efficacy of entomopathogenic nematodes. Three treatments were established: (i) both pots were irrigated at water potential ≤ -15 kPa (no drought); (ii) only the bottom pot was irrigated (partial drought); (iii) neither pot was irrigated (complete drought). Steinernema riobrave infective juveniles (IJ) were added to the soil in the top pots of all treatments. During 27 days, the water potential in soil in the top pots of both the partial and complete drought treatments declined to ca. -160 kPa. A greater number of nematodes (P ≤ 0.01) persisted in soil as motile IJ under conditions of partial drought (143/pot) than under no drought (6.1/pot) or complete drought (4.4/pot). A second experiment was initiated with the same treatments as the first, except that only half of the 20 replicates in each moisture regime were inoculated with nematodes. After 15 days, all top pots were irrigated and two larvae of the insect Diaprepes abbreviatus were added to all of the top pots in each treatment. Irrigation regimes were reinstituted until water potential in the top pots under partial and complete drought had again declined to ca. -150 kPa and the experiment was terminated. In the absence of nematodes, the damage to tap roots caused by D. abbreviatus feeding under partial drought and complete drought was 80% and 32%, respectively, of that under no drought. Numbers of motile IJ in soil were greater under conditions of partial drought (736/pot) than under complete drought (2.0/pot) or no drought (7.2/pot). Survival of D. abbreviatus and insect damage to roots were reduced by the presence of S. riobrave to a greater extent under partial drought as compared to other treatments. Hydraulic lift from the lower to the upper rhizosphere appears to have modulated the effect of dry soil conditions on feeding behavior of D. abbreviatus and created favorable conditions for persistence and efficacy of the entomopathogenic nematode.

Field and laboratory experiments were conducted to determine the degree to which free-living, bactivorous nematodes (FLBN) are able to competitively displace entomopathogenic nematodes (EPN) from insect cadavers. Two hundred larvae of the insect Diaprepes abbreviatus were buried at regular intervals during 2 years in experimental plots that were untreated or treated twice annually with Steinernema riobrave. Larvae were recovered after 7 days, and nematodes emerging from cadavers during the next 30 days were identified. The monthly prevalence of FLBN was directly related to that of S. riobrave (r = 0.38; P = 0.001) but was not related to the prevalence of the endemic EPN, S. diaprepesi, Heterorhabditis zealandica, H. indica, or H. bacteriophora (r = 0.02; P = 0.80). In a second experiment, treatment of small field plots with S. riobrave increased the prevalence of insect cadavers in which only FLBN were detected compared to untreated controls (30% vs. 14%; P = 0.052), and increased numbers of FLBN per buried insect by more than 10-fold. In the laboratory, sand microcosms containing one D. abbreviatus larva were treated with (i) the FLBN, Pellioditis sp.; (ii) S. riobrave; (iii) S. riobrave + Pellioditis; or (iv) neither nematode. Insect mortality was higher in the presence of both nematodes (57%) than when S. riobrave was alone (42%) (P = 0.01). An average of 59.2 Pellioditis sp. g(-1) insect body weight emerged in the presence of S. riobrave, whereas 6.2 nematodes g(-1) insect were recovered in the absence of the EPN (P = 0.01). Pellioditis sp. reduced the number of S. riobrave per cadaver by 84%; (P = 0.03), and per available insect by 82% (P = 0.001), compared to S. riobrave alone. Population size of S. diaprepesi was not affected by Pellioditis sp. in experiments of the same design. Faster development (P = 0.05) and nutrient appropriation within the insect cadaver by S. diaprepesi compared to S. riobrave may increase the fitness of the former species to compete with Pellioditis sp. The results of these studies demonstrate the potential of FLBN to regulate population densities of EPN and to dampen estimates of EPN-induced mortality of insect pests in the field.