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Awareness of the adverse effects of exposure to pollutant mixtures, possibly much more severe than individual chemicals, has drawn attention towards the necessity of using multi-residue methods to obtain the most possible comprehensive information on exposome. Among the different biological matrices used for exposure assessment, hair enables to detect the largest number of chemicals, including many classes such as persistent pollutants, hydrophilic metabolites and metals. Most biomonitoring studies are however focused on a limited number of pollutants and only give a partial information on exposure. Combining several multi-residue methods, the present study aimed at assessing the exposure of a population to an extensive variety of chemicals by hair analysis. One hair sample was collected from each participant (55 children and 134 adults). Samples were analysed with three different multi-residue methods, targeting, respectively, 152 organic pollutants (pesticides, PCBs, bisphenols, PBDEs), 62 polycyclic aromatic hydrocarbons (PAHs) and metabolites, nicotine and cotinine and 36 metals. From 33 to 70 organic chemicals were detected in each child’s hair sample, and from 34 up to 74 in adults. From 7 to 26 PAH were detected per child, and 7 to 21 in adults. Twenty-three to 27 metals were detected per child and 21 to 28 per adult. The highest median concentration were observed for zinc (143 μg /mg in children; 164 μg /mg in adults), bisphenol A (95.9 pg/mg in children; 64.7 pg/mg in adults) and nicotine (66.4 pg/mg in children; 51.9 pg/mg in adults). The present study provides the most comprehensive exposure assessment ever and highlights the simultaneous exposure to multiple classes of pollutants in the general population. The results support the use of multi-residue methods for future studies on exposure-associated effects, to document exposome and better consider the effect of chemical mixtures.

Knowledge gaps regarding the potential role of pesticides in the loss of agricultural biodiversity worldwide and mixture-related issues hamper proper risk assessment of unintentional impacts of pesticides, rendering essential the monitoring of wildlife exposure to these compounds. Free-ranging mammal exposure to legacy (Banned and Restricted: BRPs) and currently used (CUPs) pesticides was investigated, testing the hypotheses of: (1) a background bioaccumulation for BRPs whereas a “hot-spot” pattern for CUPs, (2) different contamination profiles between carnivores and granivores/omnivores, and (3) the role of non-treated areas as refuges towards exposure to CUPs. Apodemus mice (omnivore) and Crocidura shrews (insectivore) were sampled over two French agricultural landscapes (n = 93). The concentrations of 140 parent chemicals and metabolites were screened in hair samples. A total of 112 compounds were detected, showing small mammal exposure to fungicides, herbicides and insecticides with 32 to 65 residues detected per individual (13–26 BRPs and 18–41 CUPs). Detection frequencies exceeded 75% of individuals for 13 BRPs and 25 CUPs. Concentrations above 10 ng/g were quantified for 7 BRPs and 29 CUPs (in 46% and 72% of individuals, respectively), and above 100 ng/g for 10 CUPs (in 22% of individuals). Contamination (number of compounds or concentrations) was overall higher in shrews than rodents and higher in animals captured in hedgerows and cereal crops than in grasslands, but did not differ significantly between conventional and organic farming. A general, ubiquitous contamination by legacy and current pesticides was shown, raising issues about exposure pathways and impacts on ecosystems. We propose a concept referred to as “biowidening”, depicting an increase of compound diversity at higher trophic levels. This work suggests that wildlife exposure to pesticide mixtures is a rule rather than an exception, highlighting the need for consideration of the exposome concept and questioning appropriateness of current risk assessment and mitigation processes.

We examined factors associated with and reasons for perceived susceptibility to COVID-19 among urban and rural adults in Alabama. We surveyed 575 eligible participants’ engagement in preventive behaviors, concern about COVID-19 in their communities, perceived susceptibility to the virus, and reasons for susceptibility across three response options (Yes, No, and Don’t Know/Not Sure). Bivariate analyses compared characteristics by level of perceived susceptibility to COVID-19. A multinomial logistic regression model evaluated the association of demographics, health insurance coverage, and chronic illness status with perceived susceptibility. Participants’ race, gender, and educational attainment were significantly associated with perceived susceptibility to COVID-19. African Americans and males had higher odds of responding ‘No’, compared to ‘Yes’ and ‘Don’t Know/Not Sure’ than Whites and females. Participants with a high school education and lower had higher odds of responding ‘Don’t Know/Not Sure’ versus ‘Yes’ compared to those with college or higher education. Those unconcerned about COVID-19 in their community had higher odds of responding ‘No’ (OR = 2.51, CI 1.35–4.68) and ‘Don’t Know/Not Sure’ (OR = 2.51, CI 1.26–4.99) versus ‘Yes’, as compared to those who were concerned. Possibility of exposure at work was the most frequent reasons for perceiving themselves susceptible to COVID-19, engagement in recommended preventive measures was the most frequent reason among respondents who indicated ‘No’, and uncertainty/perception that everyone is at risk was the most frequent reason among the ones who indicated ‘Don’t Know/Not Sure’. Results indicate that tailored efforts to heighten perceived susceptibility to COVID-19 among specific demographics are needed.

Background Speciation genes contribute disproportionately to species divergence, but few examples exist, especially in vertebrates. Here we test whether Zan, which encodes the sperm acrosomal protein zonadhesin that mediates species-specific adhesion to the egg’s zona pellucida, is a speciation gene in placental mammals. Results Genomic ontogeny reveals that Zan arose by repurposing of a stem vertebrate gene that was lost in multiple lineages but retained in Eutheria on acquiring a function in egg recognition. A 112-species Zan sequence phylogeny, representing 17 of 19 placental Orders, resolves all species into monophyletic groups corresponding to recognized Orders and Suborders, with Adam2, Zp2, and Prm1), a paralogous somatic cell gene (TectA), and a mitochondrial gene commonly used for phylogenetic analyses (Cytb) all yield trees with poorer resolution than the Zan tree and inferior topologies relative to a widely accepted mammalian supertree. Zan divergence by intense positive selection produces dramatic species differences in the protein’s properties, with ordinal divergence rates generally reflecting species richness of placental Orders consistent with expectations for a speciation gene that acts across a wide range of taxa. Furthermore, Zan’s combined phylogenetic utility and divergence exceeds those of all other genes known to have evolved in Eutheria by positive selection, including the only other mammalian speciation gene, Prdm9. Conclusions Species-specific egg recognition conferred by Zan’s functional divergence served as a mode of prezygotic reproductive isolation that promoted the extraordinary adaptive radiation and success of Eutheria.

Background Culex (Culex) tritaeniorhynchus is an important vector of Japanese encephalitis virus (JEV) affecting feral pigs, native mammals and humans. The mosquito species is widely distributed throughout Southeast Asia, Africa and Europe, and thought to be absent in Australia. Methods In February and May, 2020 the Medical Entomology unit of the Northern Territory (NT) Top End Health Service collected Cx. tritaeniorhynchus female specimens (n = 19) from the Darwin and Katherine regions. Specimens were preliminarily identified morphologically as the Vishnui subgroup in subgenus Culex. Molecular identification was performed using cytochrome c oxidase subunit 1 (COI) barcoding, including sequence percentage identity using BLAST and tree-based identification using maximum likelihood analysis in the IQ-TREE software package. Once identified using COI, specimens were reanalysed for diagnostic morphological characters to inform a new taxonomic key to related species from the NT. Results Sequence percentage analysis of COI revealed that specimens from the NT shared 99.7% nucleotide identity to a haplotype of Cx. tritaeniorhynchus from Dili, Timor-Leste. The phylogenetic analysis showed that the NT specimens formed a monophyletic clade with other Cx. tritaeniorhynchus from Southeast Asia and the Middle East. We provide COI barcodes for most NT species from the Vishnui subgroup to aid future identifications, including the first genetic sequences for Culex (Culex) crinicauda and the undescribed species Culex (Culex) sp. No. 32 of Marks. Useful diagnostic morphological characters were identified and are presented in a taxonomic key to adult females to separate Cx. tritaeniorhynchus from other members of the Vishnui subgroup from the NT. Conclusions We report the detection of Cx. tritaeniorhynchus in Australia from the Darwin and Katherine regions of the NT. The vector is likely to be already established in northern Australia, given the wide geographical spread throughout the Top End of the NT. The establishment of Cx. tritaeniorhynchus in Australia is a concern to health officials as the species is an important vector of JEV and is now the sixth species from the subgenus Culex capable of vectoring JEV in Australia. We suggest that the species must now be continuously monitored during routine mosquito surveillance programmes to determine its current geographical spread and prevent the potential transmission of exotic JEV throughout Australia. Graphical abstract

Alongside the analysis of urinary metabolites which are traditional biomarkers of polycyclic aromatic hydrocarbons (PAH) exposure, the possibility of detecting PAH as well as their metabolites in hair has also recently been demonstrated. As the concentration of pollutants detected in hair is not impacted by short-term variations in exposure as can be observed with urine, it accurately represents an individual’s average level of exposure, which is the most relevant information when investigating possible linkages with biological effects. In the current study, based on a rat model exposed to a mixture of PAHs for a 90-day period, the linkage between the PAH exposure level and the resulting concentration of their metabolites in hair was then investigated. The linkage between exposure levels and the concentrations of OH-PAH in hair collected at the end of the experiment were compared to those obtained using urinary concentration of OH-PAH collected from the same animals. Linear relationship between levels of exposure and the concentration of OH-PAH in the rats’ hair (R2 0.722–0.965, p

Fatty acids (FAs), the main components of lipids, are crucial for energy storage and other physiological functions in animals and plants. Dietary FAs are incorporated and conserved in consumer tissues in predictable patterns and can be analyzed to determine the composition of an individual’s diet. This study measured the variation in FA profiles of polar cod (Boreogadus saida) across multiple years (2010–2013) over a wide geographic area in the Beaufort and Chukchi seas. Polar cod are important prey of marine mammals, sea birds, and fishes, providing a crucial link between primary producers and higher trophic-level predators. Spatial and temporal variations in FA profiles of this important forage fish species provide insight into the transfer of lipids through the Arctic ecosystem, and inform diet studies of higher trophic-level predators on polar cod that utilize trophic mixing models based on prey FA data. FA profiles of polar cod differed between the Beaufort and Chukchi seas, and among collection years. High lipid content and elevated levels of long-chain FAs in Chukchi Sea specimens relative to the Beaufort Sea may indicate more favorable feeding conditions over the years sampled, and higher energy density for Chukchi Sea polar cod as prey. FA data provide a useful metric for examining spatial and temporal variation in the quality of prey available to higher trophic-level consumers.

Although forest fragmentation is generally thought to impact tree growth and mortality negatively, recent work suggests some forests are resilient. Experimental forests provide an opportunity to examine the timing and extent of forest tree resilience to disturbance from fragmentation. We used the Wog Wog Habitat Fragmentation Experiment in southeastern Australia to test Eucalyptus growth and survivorship responses to forest fragmentation over a 26 year period. We measured 2418 tree diameters and used spline-regression techniques to examine non-monotonic fragmentation effect over two time periods. Over the first 4 years after fragmentation, individual eucalypt tree growth was greater than in continuous forest for large trees and mortality rates were higher only within 10 m of edges. Over the following 22 years only the effects on tree growth remained and on average all fragments rebounded so that their biomass and mortality rates were equivalent to continuous forest. Importantly non-monotonic patterns were observed in growth and mortality with respect to area and distance from edge in both study periods, demonstrating that fragmentation impacts on trees can be strong in localized areas (greatest in 3 ha fragments and 0–30 m edges) and over short time periods. Dry-sclerophyll eucalypt forests join the set of forest types that display resilient growth dynamics post fragmentation. Moreover, persistent non-monotonic impacts on tree growth with respect to tree size, fragment area, and fragment distance from edge, highlighting landscape fragmentation as a driver of habitat heterogeneity within remnant forest fragments.

Although hybridization between non-sibling species rarely results in viable or fertile offspring, it occasionally produces self-perpetuating or sexually-parasitic lineages in which ancestral genomes are inherited clonally and thus may persist as ‘ghost species’ after ancestor extinction. Ghost species have been detected in animals and plants, for polyploid and diploid organisms, and across clonal, semi-clonal, and even sexual reproductive modes. Here we use a detailed investigation of the evolutionary and taxonomic status of a newly-discovered, putative ghost lineage (HX) in the fish genus Hypseleotris to provide perspectives on several important issues not previously explored by other studies on ghost species, but relevant to ongoing discussions about their detection, conservation, and artificial re-creation. Our comprehensive genetic (allozymes, mtDNA) and genomic (SNPs) datasets successfully identified a threatened sexual population of HX in one tiny portion of the extensive distribution displayed by two hemi-clonal HX-containing lineages. We also discuss what confidence should be placed on any assertion that an ancestral species is actually extinct, and how to assess whether any putative sexual ancestor represents a pure remnant, as shown here, or a naturally-occurring resurrection via the crossing of compatible clones or hemi-clones.

Classical techniques for backfilling of trenches use unbounded materials. Unfortunately, they have been presenting several drawbacks regarding compaction such as noise disturbance, time of implementation and long-term settlement. In that context, controlled low strength materials could be a good alternative solution thanks to their fluidity and cementitious setting, provided that they remain excavatable, even manually with a pick. In fact, it is essential to ensure a rapid and easy permanent access to the underlying networks, in case of emergency or maintenance. Yet, the excavatability was not well defined, nor well measured so far. A fortiori, no mix design process is available to control the excavatability of these materials. It is the purpose of this article to develop one. Recently, a new approach based on a simple punching test in laboratory was proposed to provide a quantitative characterization of cement treated materials excavatability, accounting for the pick impact energy (Morin in Study of cementitious material excavatability, 2009; Morin et al. in Eur J Environ Civ Eng 17(10):935–955, 2013; Can Geotech J, 2017. https://doi.org/10.1139/cgi-2016-0534 ). The present paper first briefly describes how, in the continuation of this study, the testing set-up was improved, the approach was validated and the underlying theoretical models were calibrated on an important campaign of manual excavation on real scale trenches, in parallel with laboratory punching tests. Once the laboratory method developed, it was possible to proceed a large parametric campaign at the laboratory stage to identify the mix design parameters that influence the excavatability of cementitious materials. The second part of the paper describes the methodology used and the empirical model deduced to link the mix proportions of a cementitious material to its excavatability. Finally, manual excavations were realized on real scale trenches to confirm the relevance of the model. In conclusion, a global mix design method is proposed for excavatable cement treated materials, with a brief economical simulation.

The timing of fracture fixation in polytrauma patients has been debated for a long time. The decision between DCO (damage control orthopaedics) and ETC (early total care) is a difficult dilemma. Overzealous ETC in haemodynamically compromised patients with significant chest and head injuries can be detrimental. It has been shown, however, that early fracture fixation has a trend towards better outcome in patients with less severe injuries. Delaying all orthopaedic surgery in critically injured patients can be a safe alternative, but has several disadvantages like longer ICU stay and septic complications. The literature shows equivocal evidence for both settings. This article will summarize the historical background and controversies regarding patient assessment and decision making during the treatment of polytrauma patients. It will also give guidance for choosing DCO versus ETC in the clinical setting.

Identifying environments where invasive plants are most invasive is key to understanding causes of invasion and developing effective management strategies. In mixed-grass prairie, invasive plants are often successful in relatively wet, nitrogen-rich areas, and areas protected from grazing. Dalmatian toadflax, a common invader of mixed-grass prairie, can also be favored by high water and nitrogen availability, but is thought to be relatively unpalatable to cattle, and therefore favored by grazing. We used spatially-adjusted model selection techniques to quantify relationships between toadflax cover (measured using very high-resolution aerial imagery), and relative snow deposition (estimated with a blowing snow model), slope, aspect, soil texture, and grazing intensity (estimated by proximity to water tanks). Toadflax was common throughout the 400 ha study site, occurring in 742 of 1,861 images. Toadflax cover was high on steeper slopes, particularly those with southern aspects. These two topographic variables were more effective in explaining toadflax distribution than modeled snow deposition, suggesting that factors other than snow deposition cause toadflax invasion on south-facing slopes. Toadflax cover was also high in areas further from water tanks, indicating that grazing may inhibit toadflax invasion. More broadly, this result suggests that grazing can reduce invasion of even relatively unpalatable species in ecosystems with long evolutionary histories of grazing.

The last decade has seen an increase in the frequency and breadth of application of molecular tools, many of which are beginning to shed light on long-standing questions in biogeography and evolutionary history of marine fauna. We explore new developments with respect to Arctic marine invertebrates, focusing on molecular taxonomy and phylogeography—two areas that have seen the most progress in the time-frame of the Census of Marine Life. International efforts to generate genetic ‘barcodes’ have yielded new taxonomic insights and applications ranging from diet analysis to identification of larval forms. Increasing availability of genetic data in public databases is also facilitating exploration of large-scale patterns in Arctic marine populations. We present new case-studies in meta-population analysis of barcode data from polychaetes and echinoderms that demonstrate such phylogeographic applications. Emerging patterns from ours and other published studies include influences of a complex climatic and glacial history on genetic diversity and evolution in the Arctic, and contrasting patterns of both high gene flow and persistent biogeographic boundaries in contemporary populations.

We investigated the influence of intracellular diffusion on muscle fiber design in several swimming and non-swimming brachyuran crabs. Species with sustained swimming behavior had aerobic dark fibers subdivided into small metabolic functional units, creating short diffusion distances necessary to support the high rates of aerobic ATP turnover associated with endurance activity. This dark fiber design was observed in all swimming species including Ovalipes ocellatus, which has apparently evolved swimming behavior independently of other Portunidae. In addition, we observed fiber and subdivision size-dependent differences in organelle distribution. Mitochondria, which rely on oxygen to function, were uniformly distributed in small fibers/subdivisions, but were clustered at the fiber periphery in larger fibers. The inverse pattern was observed for nuclei, which are not oxygen dependent, but rely on the transport of slow diffusing macromolecules. Phylogenetically independent contrast analysis revealed that these relationships were largely independent of phylogeny. Our results demonstrate cellular responses to diffusion that were necessary for the evolution of swimming and that are likely to be broadly applicable.

The objective of this retrospective study of prospectively registered patients was to determine the usefulness and efficacy of noninvasive ventilation (NIV) in cancer patients admitted to the medical intensive care unit of an European cancer hospital for a medical complication, as reflected in discharges from the intensive care unit (ICU) and from hospital. The subjects were a total of 40 consecutive cancer patients (28 with solid tumours and 12 with haematological malignancies) who required immediate or delayed NIV. Variables relating to demographic parameters, severity scores, cancer characteristics, intensive care data and hospital discharge were recorded. The complications making NIV necessary were hypoxaemic pneumonia in 32.5%, hypercapnic ventilatory failure in 30%, multifactorial respiratory failure in 17.5%, acute haemodynamic oedema in 10%, acute respiratory distress syndrome in 2.5%, alveolar haemorrhage in 2.5%, pulmonary embolism in 2.5% and lysis pneumopathy in 2.5%. Most of the patients, 57.5% and 42.5%, respectively, were discharged from the ICU and from the hospital. Among the 10 patients (25%) who required salvage invasive mechanical ventilation, only 1 was discharged from hospital. Sixty-four per cent of the solid tumour patients and 42% of those with haematological malignancies were discharged from the ICU and 50% and 25%, respectively, from the hospital. NIV thus appears to be an effective form of ventilatory support for cancer patients, including those with solid tumours.

A method for the determination of PAHs in aqueous media based on synchronous fluorescence analysis directly on a solid phase after extraction was evaluated. Tests were conducted for (i) the simultaneous analysis of naphthalene, phenanthrene, anthracene, and pyrene in water at a parts per billion concentration level using a 0V1 sorbing phase block and (ii) the analysis of 1-hydroxyphenanthrene (1-OHPh) and 1-hydroxypyrene (1-OHPy) in human urine using a small sheet cut from a C18 silica fiberglass extraction disk (ENVI-Disk). Because the linear dynamic concentration range is dependent on both the immersion time and the concentration range, in all cases, an optimum immersion time must be determined to preserve linearity of intensity versus concentration. Calibration curves were determined for a concentration lower than 15 ppb in the case of 1-OHPh and at a concentration lower than 1.5 ppb in the case of 1-OHPy. In all cases the limits of detection were estimated to be lower than 0.2 ppb, i.e., for 1-OHPh and 1-OHPy, in the lowest concentration limit these metabolites were found in the urine of persons unexposed or weakly exposed to PAHs.

International audience; The mitochondrial genetic variability in European rabbit (Oryctolagus cuniculus) populations present in Europe and North Africa from 11,000 years ago to the present day has been analyzed using ancient DNA techniques. DNA was extracted from 90 rabbit bones found in 22 archaeological sites dated between the Mesolithic and recent times. Nucleotide sequences present in a variable 233-bp domain of the cytochrome b gene were compared to those present in modern-day rabbits. The results show that the structure of ancient populations of wild rabbit exhibited remarkable stability over time until the Middle Ages. At this time, a novel type of mtDNA molecule abruptly appears into most wild populations studied from France. This mtDNA type corresponds to that currently present in the domestic breeds of rabbit examined so far. The relative rapidity by which this mtDNA type established and its absence in all sites examined before 1,700 years ago lend support to the hypothesis that between 2,000 and 1,000 years ago, man may have favored the development, into all regions of France, of animals carrying this particular mtDNA molecule. The origin of such animals has still to be found: animals previously living outside of France or within France but in very restricted areas? This event was concomitant with the documented establishment of warrens after the tenth century A.D. in Europe.

Methods The study was a longitudinal observational, cohort study with data collected at baseline and three months. Nine integrative medicine clinics housed at academic health centers that were members of the Consortium for Academic Health Centers for Integrative Medicine (CAHCIM) were invited to participate. Each academic health center was asked to obtain IRB approval for the study. Clinic patients enrolled in the study were given instructions for logging on to the project website to complete the following questionnaires: demographic, quality of life (SF-12), brief pain inventory, and an evaluation of the web-based system. Three months after completing baseline questionnaires patients were notified by email with instructions to complete final quality of life and pain questionnaires. Change in quality of life and pain were analyzed by paired t-test.

The re-emergence of the tumour growth factor-beta (TGF-beta)-related embryonic morphogen Nodal has recently been reported in several different human cancers. In this study, we examined the expression of Nodal in a series of benign and malignant human breast tissues to determine the clinical significance of this expression and whether Nodal could represent a potential therapeutic target in breast cancer. Tissue sections from 431 therapeutically naive patients diagnosed with benign or malignant breast disease were stained for Nodal by immunohistochemistry and analysed in a blinded manner. The degree of Nodal staining was subsequently correlated with available clinical data, such as diagnoses and disease stage. These tissue findings were further explored in breast cancer cell lines MDA-MB-231 and MDA-MB-468 treated with a Nodal blocking antibody to determine biological effects for target validation. A variable degree of Nodal staining was detected in all samples. The intensity of Nodal staining was significantly greater in undifferentiated, advanced stage, invasive breast cancer compared with benign breast disease or early stage breast cancer. Treatment of human breast cancer cells in vitro with Nodal blocking antibody significantly reduced proliferation and colony-forming ability in soft agar, concomitant with increased apoptosis. These data suggest a potential role for Nodal as a biomarker for disease progression and a promising target for anti-Nodal therapy in breast cancer.

International audience; The European rabbit (Oryctolagus cuniculus) is now widely distributed throughout the world as a result of transportation by man. The original populations, however, were confined to southern France and Spain. In order to investigate the role of human intervention in determining the genetic diversity of rabbit populations, we are studying the origin of rabbits introduced onto a small Mediterranean island (Zembra) near Tunis over 1400 years ago, by examining ancient DNA extracted from rabbit bones found both on Zembra and on the European mainland. Ancient DNA was successfully extracted from rabbit bones found at two archaeological sites dated to at least the Early Bronze Age (more than 3500 years ago) in south-central France, and compared to that found in modern mainland and island populations using a small variable region of the cytochromeb gene. The results confirm that the Zembra Island population is descended from that present over 1400 years ago. The technical aspects of DNA extraction from bones and the implications of this type of research for determining the origin of introduced rabbit populations are discussed.

The cytochrome oxidase subunit 1 gene (COX1) in K. lactis K8 mtDNA spans 8,826 bp and contains five exons (termed E1-E5) totalling 1,602 bp that show 88% nucleotide base matching and 91% amino acid homology to the equivalent gene in S. cerevisiae. The four introns (termed K1 cox1.1-1.4) contain open reading frames encoding proteins of 786, 333, 319 and 395 amino acids respectively that potentially encode maturase enzymes. The first intron belongs to group II whereas the remaining three are group I type B. Introns K1 cox1.1, 1.3, and 1.4 are found at identical locations to introns Sc cox1.2, 1.5 a, and 1.5 b respectively from S. cerevisiae. Horizontal transfer of an intron between recent progenitors of K. lactis and S. cerevisiae is suggested by the observation that K1 cox1.1 and Sc cox1.2 show 96% base matching. Sequence comparisons between K1 cox1.3/Sc cox1.5 a and K1 cox1.4/Sc cox1.5 b suggest that these introns are likely to have been present in the ancestral COX1 gene of these yeasts. Intron K1 cox1.2 is not found in S. cerevisiae and appears at an unique location in K. lactis. A feature of the DNA sequences of the group I introns K1 cox1.2, 1.3, and 1.4 is the presence of 11 GC-rich clusters inserted into both coding and noncoding regions. Immediately downstream of the COX1 gene is the ATPase subunit 8 gene (A8) that shows 82.6% base matching to its counterpart in S. cerevisiae mtDNA.

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The drastically reduced virus yields obtained from monkey cells abortively infected with adenovirus 2 (Ad2) have been attributed primarily to a severe decrease in the accumulation of the virion protein fiber (IV), a product of the most pomoter distal late gene family, L5. Here we report that the accumulation of virion protein IIIa, a product of the proximal late gene family, L1, is also severely depressed. In contrast, the i-leader protein LO-13.6K and L1 protein(s) 52K/55K are expressed with the same time course and in equal amounts in monkey cells abortively infected by Ad2 or productively infected by the Ad2-simian virus 40 (SV40) hybrid Ad2+ND1 or by the host range mutant Ad2+ND3 hr602. L1-52K/55K is phosphorylated in abortively infected CV-1 or CV-C monkey cells as well as in productively infected human and monkey cells. As with fiber expression, the failure to produce IIIa appears to be due partly to reduced or delayed IIIa mRNA accumulation. The small amount of IIIa protein that is synthesized in monkey cells is stable. Since the accumulation of both IIIa and fiber protein is deficient, the mechanism of abortive infection cannot be attributed solely to the absence of the auxiliary fiber leader sequences (1).

Conformational energy computations of the monopeptides from three achiral α,α-dialkylated glycyl residues with acyclic side chains (namely α,α-dimethyl-; α,α-diethyl-; and α, α-di-n-propylglycines) are reported as a function of the relevant N-Cα-C′ bond angle. In parallel, experimental studies were performed in the solid state (infrared absorption and X-ray diffraction) and in solution (infrared absorption and proton magnetic resonance) on the corresponding protected homo-peptide series (the former series to the dodecamer, the other two series to the pentamers). The results obtained unequivocally indicate that the preference from a helical to a fully extended conformation increases as side-chain bulkiness increases. The longest homo-peptides from α,α-dimethylglycine form stable 310-helices. A picture of the mode of self-association of the helical structures has also been determined. The results of the theoretical analyses fit well with the experimentally observed conformational properties in the solid state and in chloroform solution.

Three classes of respiratory deficient mutants have been isolated from a fusant between Kluyveromyces lactis and Saccharomyces cerevisiae that contains only K. lactis mtDNA. One class (15 isolates), resemble rho 0 mutants of S. cerevisiae as they lack detectable mtDNA. A second class (16 isolates), resemble point mutations (mit-) or nuclear lesions (pet-) of S. cerevisiae as no detectable change is found in their mtDNA. The third class (five isolates), with deletions and rearrangements in their mtDNA are comparable to S. cerevisiae petite (rho-) mutants. Surprisingly, three of the five deletion mutants have lost the same 8.0 kb sector of the mtDNA that encompasses the entire cytochrome oxidase subunit 2 gene and the majority of the adjacent cytochrome oxidase subunit 1 gene. In the other strains, deletions are accompanied by complex rearrangements together with substoiciometric bands and in one instance an amplified sector of 800 bp. By contrast to G + C rich short direct repeats forming deletion sites in S. cerevisiae mtDNA, excision of the 8.0 kb sector in K. lactis mtDNA occurs at an 11 bp A + T rich direct repeat CTAATATATAT. The recovery of three strains manifesting this deletion suggests there are limited sites for intramolecular recombination leading to excision in K. lactis mtDNA.

Through steep increase of work load, problems arise in the chemical pathology laboratory which are discussed. Using the newly designed units of Limited Function Automation System, Diluters and Dispensers, a new way is announced leads to increase in accuracy and reproducibility of the manual method used hitherto. This is supplemented also by increase in speed and efficiency, and it results, in general, in greatly increased work capacity without additional need for increase in staff. Compared with fully automated continuous analysing systems this system of L. F. A. is favoured in as much that it is inexpensive and requires no especially experienced or trained staff for running.

IT has been postulated that an amylase inhibitor exists in normal human serum, but not in the serum of patients with acute pancreatitis1. The principal evidence for the presence of this inhibitor was based on observations that the average amylase activity of a group of sera was nearly tripled after subjecting the specimens to filter paper electrophoresis. It was found that when eighteen normal sera having a mean amylase value of 106 Somogyi units were separated electrophoretically, the total amylase recovered by extracting the various protein fractions with saline averaged 311 Somogyi units1. However, a similar electrophoretically-induced enhancement in amylase activity could not be demonstrated in sera from patients with acute pancreatitis. Dreiling et al.2 substantiated these observations and suggested that although increased quantities of pancreatic amylase enter the blood in acute pancreatitis, the circulating level of the amylase inhibitor is decreased in this disorder. These workers further concluded that, in cases of pancreatic cancer, hyperamylasaemia was not accompanied by any diminution in the enzyme inhibitor.

AN increasing interest is being shown in serum oxyto-cinase (l-cystine-aminopeptidase (3.4.1.2.)) levels in pregnancy, yet the methods described in recent papers1,2 for its determination seem unnecessarily laborious. We have for some time now been using the modification described here. It is based on the method used for the determination of l-leucine-aminopeptidase (3.4.1.1.) activity in serum3–5, now used as a routine biochemical investigation for which commercial test kits have been developed, such as that of Boehringer, Biochemica, Mannheim, which we use.

THE behaviour of amino-acids in high-tension (100–300 V./cm.) electrostatic fields has recently been investigated in this laboratory. A phenomenon (to be described shortly) was observed, and it led to a hypothesis which is summarized in the following.

Chronic self-mutilation and aggression is a medically important and sometimes life threatening behavioral disorder in adolescents with profound intellectual deficits. In 40 institutionalized mentally retarded patients, lithium carbonate proved beneficial in relieving targeted aggressive behaviors in 35%, unhelpful in 28%, temporarily useful in 25%, and indeterminate in 12%. In the patients showing a beneficial response, a cyclical pattern of aggressive outbursts was seen in 86%, a history of sleep disturbance in 93%, and a positive family history of psychiatric disease in 71%. No serious side effects were noted during the period of medication. In 3 patients who proved refractory to therapeutic dosages of lithium carbonate, an operant conditioning program was implemented as follows: (1) reinforcement of nondestructive behaviors, (2) development and shaping of socially desirable behaviors, (3) training in muscle relaxation and vigilance, and (4) a generalization program to allow maintenance of therapeutic gains by nonmedical caretakers. Medically significant self-abuse ceased in all patients within 5 days, and each achieved greater than 90% compliance with a graded series of self-care tasks within 14 days. Abstinence from self-injury has been complete for up to 40 months. Lithium carbonate and/or the above behavioral program prove highly effective in controlling aggressive behavior in the mentally retarded. (Supported in part by USPHS grants HD 05515 and HD 04147)

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