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Some animals have evolved task differentiation among their eyes. A particular example is spiders, where most species have eight eyes, of which two (the principal eyes) are used for object discrimination, whereas the other three pairs (secondary eyes) detect movement. In the ctenid spider Cupiennius salei, these two eye types correspond to two visual pathways in the brain. Each eye is associated with its own first- and second-order visual neuropil. The second-order neuropils of the principal eyes are connected to the arcuate body, whereas the second-order neuropils of the secondary eyes are linked to the mushroom body. We explored the principal- and secondary eye visual pathways of the jumping spider Marpissa muscosa, in which size and visual fields of the two eye types are considerably different. We found that the connectivity of the principal eye pathway is the same as in C. salei, while there are differences in the secondary eye pathways. In M. muscosa, all secondary eyes are connected to their own first-order visual neuropils. The first-order visual neuropils of the anterior lateral and posterior lateral eyes are connected with a second-order visual neuropil each and an additional shared one (L2). In the posterior median eyes, the axons of their first-order visual neuropils project directly to the arcuate body, suggesting that the posterior median eyes do not detect movement. The L2 might function as an upstream integration center enabling faster movement decisions.

Background The surgical approaches remain controversial for the treatment of middle and distal-third humeral shaft (MDTHS) fractures. This study compared clinical effects of the anterolateral approach with two incisions (AATI) and the posterior median approach (PMA) in the treatment of MDTHS fractures. Methods A retrospective analysis was carried out. One hundred sixty-six patients with MDTHS fractures were selected from January 2015 to January 2017 in Xi’an Hong Hui Hospital. According to surgical approaches, patients were divided into AATI (86 cases) and PMA group (80 cases). All patients were treated with open reduction and plate fixation. Operation indexes were compared, including incision length, operation time, and bleeding. Bryan-Morrey score was used to evaluate elbow joint function. Complication incidence was compared, such as incision infection, iatrogenic radial nerve injury, and nonunion. Results The AATI group showed smaller incision length, less bleeding, lower iatrogenic radial nerve injury rate, and better elbow function than that of PMA group (P Conclusions The middle and distal-third humeral shaft fractures can be successfully cured by both approaches. Compared with the posterior median approach, it has better clinical effects of the anterolateral approach with two incisions, which is worthy of clinical application and promotion.

A new genus and three new species of the spider family Palpimanidae Thorell, 1870 from Kenya are described. Sceliscelis Oketch & Li, gen. nov. is close to Sarascelis Simon, 1887 and Scelidocteus Simon, 1907 but differs in the structure of the male palp. The new species reported are Sceliscelis marshi Oketch & Li, sp. nov., Scelidocteus taitave Oketch & Li, sp. nov., and Hybosida machondogo Oketch & Li, sp. nov.Sceliscelis marshisp. nov. is described from males and females collected from Tsavo in south Kenya. Scelidocteus taitavesp. nov. can be distinguished from other congeners, as well as from the morphologically similar Scelidomachus socotranus Pocock, 1899, by the shape of the palpal “conductor”. Hybosida machondogosp. nov. differs from other six-eyed Hybosida spp. by possessing rudimentary posterior median eyes.

Cylindrical silk gland (CY) spigots distinguish a large clade of modern spiders, the CY spigot clade, which includes all entelegyne spiders and their closest relatives. Following a widespread paradigm, CYs and their spigots are only known to occur in female spiders and they produce silk used in the construction of egg sacs. Here we report the occurrence of a CY spigot or CY nubbin on each posterior median spinneret (PMS) in males (5th stadium and later) of the spider Australomimetus maculosus. Late juvenile males had a CY spigot on each PMS, whereas adult males either had a CY spigot or, more often, a non-functional CY nubbin. This indicates that potential CY use by males is at least largely limited to late juvenile instars and is not involved with egg sac construction. Despite the presence of CY spigots in both sexes, sexual dimorphism with respect to CYs was still evident since males lacked the CY spigot on each posterior lateral spinneret present in late juvenile and adult females, and CY spigots of males never had the wide shaft and opening of adult females. This study adds to our knowledge of spinning apparatus variability in modern spiders and demonstrates an exception to the paradigm that, in the CY spigot clade, such spigots are restricted to female spiders.

Stable isotope mixing models (SIMMs) provide a powerful methodology for quantifying relative contributions of several sources to a mixture. They are widely used in the fields of ecology, geology, and archaeology. Although SIMMs have been rapidly evolved in the Bayesian framework, the underdetermination of mixing space remains problematic, i.e., the estimated relative contributions are incompletely identifiable. Here we propose a statistical method to quantitatively diagnose underdetermination in Bayesian SIMMs, and demonstrate the applications of our method (named β-dependent SIMM) using two motivated examples. Using a simulation example, we showed that the proposed method can rigorously quantify the expected underdetermination (i.e., intervals of β-dependent posterior) of relative contributions. Moreover, the application to the published field data highlighted two problematic aspects of the underdetermination: 1) ordinary SIMMs was difficult to quantify underdetermination of each source, and 2) the marginal posterior median was not necessarily consistent with the joint posterior peak in the case of underdetermination. Our study theoretically and numerically confirmed that β-dependent SIMMs provide a useful diagnostic tool for the underdetermined mixing problem. In addition to ordinary SIMMs, we recommend reporting the results of β-dependent SIMMs to obtain a biologically feasible and sound interpretation from stable isotope data.

Despite the recognition of spider silk as a biological super-material and its dominant role in various aspects of a spider&rsquo, s life, knowledge on silk use and silk properties is incomplete. This is a major impediment for the general understanding of spider ecology, spider silk evolution and biomaterial prospecting. In particular, the biological role of different types of silk glands is largely unexplored. Here, I report the results from a comparative study of spinneret usage during silk anchor and dragline spinning. I found that the use of both anterior lateral spinnerets (ALS) and posterior median spinnerets (PMS) is the plesiomorphic state of silk anchor and dragline spinning in the Araneomorphae, with transitions to ALS-only use in the Araneoidea and some smaller lineages scattered across the spider tree of life. Opposing the reduction to using a single spinneret pair, few taxa have switched to using all ALS, PMS and the posterior lateral spinnerets (PLS) for silk anchor and dragline formation. Silk fibres from the used spinnerets (major ampullate, minor ampullate and aciniform silk) were generally bundled in draglines after the completion of silk anchor spinning. Araneoid spiders were highly distinct from most other spiders in their draglines, being composed of major ampullate silk only. This indicates that major ampullate silk properties reported from comparative measurements of draglines should be handled with care. These observations call for a closer investigation of the function of different silk glands in spiders.

In neuroanatomy textbooks on humans, the posterior median septum is commonly depicted along the midline of the posterior column of the spinal cord. For intramedullary spinal cord tumors, the standard surgical treatment is posterior midline myelotomy. However, its anatomical basis is still unclear. Therefore, in this study we focused on the ultrastructural characterization of the median structure of the posterior column in an adult rat. In the median part of the fasciculi gracilis, a fine lineal tissue continued from the posterior median sulcus to the 3/4th depth of the fasciculi. At higher magnification, this fine lineal tissue consisted of bundles of astrocytes, which are often disrupted and eventually disappeared. At the junction of the ventral part of the fasciculi cuneatus and the gray commissure, short lineal figures of glial tissues extended dorsally. These lineal figures of glial tissues were morphologically similar to other lineal figures of glial tissues found in the posterior column; bundles of astrocytes extending along the axons that entered the gray commissure and the perivascular lineal figures of glial tissues. In conclusion, this study revealed that the posterior median septum is composed of very fine lineal figures of glial tissues that are often disrupted and eventually disappear. We consider these basic structures to be similar in humans. Therefore, during posterior midline myelotomy, accurately separating along the posterior median septum in the posterior column is extremely difficult.

Pseudonemesia tabiskey sp. nov. is described from an Andean Forest in Trujillo, Venezuela. The new species is the third for the genus and differs from the other two species by the presence of one short and apically rounded modified seta on the retrolateral distal portion of the male tibia I and clavate setae on the dorsal and lateral sides of abdomen in both sexes. A new diagnosis is given to Pseudonemesia and new morphological data based on scanning electron microscopy for the Microstigmatinae are presented. The presence of posterior median spinnerets in Pseudonemesia is discussed.

Agelenidae is a species rich and globally-distributed spider family comprising 1274 species in 77 genera (World Spider Catalog 2018). In Iran, this family is currently represented by eight species in four genera (Zamani et al. 2018). Being the second largest genus of the family (after Draconarius Ovtchinnikov, 1999), Tegenaria Latreille, 1804, currently encompasses 105 species that are primarily distributed in the Palaearctic (World Spider Catalog 2018; Marusik & Zamani 2015). So far, four species of this genus are known from Iran: Tegenaria domestica (Clerck, 1758) (western, northern, central and eastern Iran), T. lenkoranica (Guseinov et al., 2005) (northern Iran), T. pagana C.L. Koch, 1840 (northern Iran), and the endemic T. zamanii Marusik et Omelko, 2014 (northern Iran) (Zamani et al. 2018). Two of these species, T. lenkoranica and T. zamanii have been reported from caves (Malek-Hosseini & Zamani 2017). Considering the lack of studies on this genus in Iran, many species are undoubtedly awaiting to be discovered. During the biospeleological investigations of Zagros Mountains, a new species of Tegenaria was collected in western Iran, which is described and illustrated in this paper. The specimens were photographed using an Olympus Camedia E-520 camera attached to an Olympus SZX16 stereomicroscope and digital images were prepared using “CombineZP” image stacking software. Leg ratios were measured on the dorsal side and all measurements are given in millimeters. Measurements of leg are listed as: total length (femur, patella, tibia, metatarsus, tarsus). Standard abbreviations were used for the eyes: AME, anterior median eyes; ALE, anterior lateral eyes; PME, posterior median eyes; PLE, posterior lateral eyes. The specimens will be deposited in the Manchester Museum of the University of Manchester (MMUE).

The authors report simultaneous surgical treatment of the right S1 root schwannoma with extravertebral retroperitoneal spread. Well-equipped operating theatre, professional experience and multidisciplinary approach involving neurosurgeons and abdominal surgeons ensure total minimally invasive simultaneous resection of schwannoma via posterior median and laparoscopic approach.Представлено клиническое наблюдение симультанного оперативного лечения невриномы правого спинномозгового корешка S1 с экстравертебральным ретроперитонеальным распространением. Операционная, полностью оснащенная современным хирургическим оборудованием, профессиональный опыт и мультидисциплинарный подход к лечению у нейрохирургов и абдоминальных хирургов позволили выполнить радикальное, минимально инвазивное одномоментное удаление образования из заднего срединного и лапароскопического доступа.

Although associated with a higher approach-related traumatic impact on the soft tissue of the neck than the anterior approach, the posterior median approach to the subaxial cervical spine remains standard for numerous indications. Reported procedure-related complications in posterior cervical surgical interventions can be significantly reduced by appropriate preoperative planning and patient positioning as also by a straightforward surgical approach technique and wound closure. Inadvertence during dissection leads to higher blood loss and extended surgical time; has a collateral impact on clinical outcomes, infection and revision rates; and might lead to adjacent segment degeneration and instability. Thus, the aim of the article is to present technical nuances and tips for complication avoidance related to the posterior median access to the subaxial spine.

A hydrologic uncertainty processor (HUP) that the prior density and likelihood function are explicitly expressed is introduced based on a copula function. The results show that the copula-based HUP is comparable to the meta-Gaussian HUP regarding the posterior median forecasts. Besides, the probabilistic forecasts produced by the copula-based HUP have slightly higher reliability and lower resolution, as compared to those of the meta-Gaussian HUP. A Copula Bayesian processor associated with the Bayesian model averaging (CBP-BMA) method is used with ensemble lumped hydrological models. Compared with the BMA and Copula-BMA methods, the CBP-BMA method relaxes any assumption on the distribution of conditional PDFs. The case study results demonstrate that the CBP-BMA method can improve hydrological forecasting precision with higher coverage ratios. The copula-based HUP and CBP-BMA methods provide alternative approaches to uncertainty analysis of hydrological forecasts.

The Neotropical Sasoninae Neodiplothele Mello-Leitão, 1917 is revised and now includes eight species. Neodiplothele can be distinguished from other Sasoninae by the absence of the posterior median spinnerets and differs Neotropical relatives as Cosmopelma by the absence of cuspules on coxae of leg I and Paracenobiopelma by the absence of cuspules on the labium. The male of N. irregularis Mello-Leitão, 1917 and N. picta Vellard, 1924 are described and illustrated for the first time. Neodiplothele leonardosi Mello-Leitão, 1939 is considered a junior synonym of N. irregularis. Five new species are described from Brazil: N. aureus sp. nov. from the states of Ceará, Rio Grande do Norte, Paraíba, and Minas Gerais, N. itabaiana sp. nov. from Sergipe, N. martinsi sp. nov. from Bahia, Espírito Santo, and Minas Gerais, N. indicattii sp. nov. from Espírito Santo, Minas Gerais, Rio de Janeiro, and São Paulo, N. caucaia sp. nov. from Ceará, Goiás, and Mato Grosso do Sul. Two informal groups are proposed based on genitalia morphology: irregularis group and picta group. An identification key and new distribution records for all known species are given.

Roughly half of Bayes’s famous essay was written by Richard Price, including the Appendix with all of the numerical examples. A study of this Appendix reveals Price (1) unusually for the time, felt it necessary to allow in his analysis for a hypothesis having been suggested by the same data used in its analysis, (2) was motivated (covertly in 1763, overtly in 1767) to undertake the study to refute David Hume on miracles, and (3) displayed a remarkable sense of collegiality in scientific controversy that should stand as a model for the present day. Price’s analysis of the posterior in one particular example, including locating the posterior median and giving and interpreting credible regions, qualifies him as the first person to apply Bayes’s theory.

Background Species of Diplozoon Palombi, 1949 (Monogenea: Diplozoidae) are blood-feeding ectoparasites mainly parasitising the gills of cyprinid fishes. Although these parasites have been the subject of numerous taxonomic, phylogenetic and ecological studies, the ultrastructure of the surface and haptor attachment structures remains almost unknown. In this study, we used transmission electron microscopy to examine the ultrastructure of attachment clamps and neodermal surface of Paradiplozoon homoion (Bychowsky & Nagibina, 1959), family Diplozoidae Palombi, 1949, thereby broadening our knowledge of platyhelminth biology. Results The hindbody surface of P. homoion is distinctly ridged, each ridge being supported by several muscle fibers and equipped with scales on the surface plasma membrane. Such structures have not been recorded previously in species of the family Diplozoidae. Comparisons of the surface structure of different body parts revealed slight differences in the thickness and number of organelles. Each of the clamps has a flattened bowl-like structure composed of sclerites, movable skeletal-like structures that are anchored by robust, radially oriented muscle bundles. The base of the posterior median plate sclerites is equipped with glandular cells possessing secretory vesicles. Conclusion This study brings detailed ultrastructural data for the surface and haptoral attachment clamps of P. homoion and provides new insights into the ultrastructure of Diplozoidae. Glandular cells at the base of the attachment clamps responsible for sclerite development in diplozoid species were observed for the first time. Our findings support the hypothesis that the structure of particular neodermal compartments is similar within the Platyhelminthes. On the other hand, the diplozoid glandular system and the mechanism of sclerite development clearly merits further attention.

The aim of this study was to analyze the topographical anatomy of the dorsal spinal cord (SC) in relation to the posterior median septum (PMS). This included the course and variations in the PMS, and its relationship to and distance from other dorsal spinal landmarks. Microsurgical anatomy of the PMS was examined in 12 formalin-fixed adult cadaveric SCs. Surface landmarks such as the dorsal root entry zone (DREZ), the denticulate ligament, the architecture of the leptomeninges and pial vascular distribution were noted. The PMS was examined histologically in all spinal segments. The PMS extended most deeply at spinal segments C7 and S4. This was statistically significant for all spinal segments except C5. The PMS was shallowest at segments T4 and T6, where it was statistically significantly thinner than at any other segment. In 80% of the SCs, small blood vessels were identified that traveled in a rostrocaudal direction in the PMS. The longest distance between the PMS and the DREZ was at the C1–C4 vertebral levels and the shortest distance was at the S5 level. Prevention of deficits following a dorsal midline neurosurgical approach to deep-seated SC lesions requires careful identification of the midline of the cord. The PMS and septum define the midline on the dorsum of the SC and their accurate identification is essential for a safe midline surgical approach. In this anatomical study, we describe the surface anatomy of the dorsal SC and its relationship with the PMS, which can be used to determine a safe entry zone into the SC. Clin. Anat. 28:45–51, 2015. © 2014 Wiley Periodicals, Inc.

The wolf spider Lycosa tarantula returns home by means of path integration. Previous studies demonstrated: (i) that the angular component of the outbound run is measured using a polarized-light compass associated with the anterior median eyes; (ii) changes in direction of the substratum are detected by the anterior lateral eyes (ALEs); and (iii) in relation to the linear component of the outbound run, an increase of optic flow, in either the lateral or ventral fields of view, caused spiders to search for the burrow at a point nearer to the goal. However, the role of the secondary eyes [ALEs, posterior lateral eyes (PLEs) and posterior median eyes (PMEs)] in the perception of this optic flow and the importance of them for gauging the distance walked is still unknown. In this study, lateral or ventral gratings of wavelength λ=1 cm were used, with two groups of spiders in each setup: (1) PLEs+PMEs covered and (2) ALEs covered. The largest reduction in the distance walked to return to the burrow was observed with the ventral grating/ALEs covered. These results show the importance of the previously neglected ALEs for the visual behavior of these spiders. The possibility of gathering information for locomotion from the three pairs of secondary eyes in the mushroom bodies is discussed.

Sign restrictions on the responses generated by structural vector autoregressive models have been proposed as an alternative approach to the use of exclusion restrictions on the impact multiplier matrix. In recent years such models have been increasingly used to identify demand and supply shocks in the market for crude oil. We demonstrate that sign restrictions alone are insufficient to infer the responses of the real price of oil to such shocks. Moreover, the conventional assumption that all admissible models are equally likely is routinely violated in oil market models, calling into question the use of posterior median responses to characterize the responses to structural shocks. When combining sign restrictions with additional empirically plausible bounds on the magnitude of the short-run oil supply elasticity and on the impact response of real activity, however, it is possible to reduce the set of admissible model solutions to a small number of qualitatively similar estimates. The resulting model estimates are broadly consistent with earlier results regarding the relative importance of demand and supply shocks for the real price of oil based on structural vector autoregressive (VAR) models identified by exclusion restrictions, but imply very different dynamics from the posterior median responses in VAR models based on sign restrictions only.

Loricaria coximensis, new species, is described from the Rio Paraguay basin, in Mato Grosso do Sul State, Brazil. It is distinguished from all other species of Loricaria, except L. holmbergi, L. lundbergi, L. parnahybae, and L. pumila by having abdominal plates confined to the pre-anal shield and posterior median abdominal area, usually loosely joined or separated by naked areas, pectoral girdle mostly naked, with isolated plates near base of pectoral fins and posterior to gill opening vs. abdominal plates well developed and tightly arranged across the entire median abdominal area, including the pectoral girdle. It is distinguished from these other four species by meristic counts and several morphometric proportions, particularly a broader head (19.4–21.3% SL vs. 14.1–19.1% SL). Loricaria coximensis becomes the third described paedomorphic species of Loricaria, along with L. nickeriensis and L. pumila, based on its small adult size (

A new basal antiarch, Silurolepis platydorsalis n. gen. n. sp., represented by a large-sized trunk armor and a disassociated anterior median dorsal plate (AMD), is described from the Ludlow (Silurian) of Qujing, Yunnan, southwestern China. It is characterized by its AMD overlapping the posterior median dorsal plate, broad anterior margin of the AMD, and crest-shaped dorsolateral ridge of the trunk armor. As the oldest known articulated placoderm fish to date, the new fish provides new insights into the early evolution of antiarchs.

The scorpion Apistobuthus susanae Lourenco 1998 is redescribed based on new specimens collected from Khoozestan Province, Iran. It is distinct from A. pterygocercus Finnegan 1932 found in the dunes of Rub' al-Khali. The two species cannot be separated by previously used diagnostic characters. Instead, A. susanae is differentiated from A. pterygocercus by new characters, including more robust legs and pedipalps, shorter pectines, stronger carination, and complete fusion of central lateral and posterior median carinae of the carapace.

Two new species, Opopaea viamao and O. ita, are described from the states of Rio Grande do Sul and Santa Catarina, Brazil, respectively. Both species present reduction or loss of posterior median eyes, a possible synapomorphic caracter.

The monotypic diplurid Metriura Drolshagen & Backstam, 2009 is placed in synonymy with Fufius (Cyrtaucheniidae) syn. nov. since Metriura lacks two of three diplurid synapomorphies (elongate posterior lateral spinnerets and the widely separated posterior median spinnerets) and shares synapomorphies with both aporoptychine cyrtaucheniids (subquadrate maxilla and a longer than wider labium) and Fufius (recurved and broad fovea, the typical incrassate tibia I of the male, with the spur having a single short branch and an apical megaspine, the basally curved metatarsus I and provided with a ventral tubercle). The type species of Metriura, M. striatipes Drolshagen & Backstam, 2009 is considered valid, and due to the synonymy of Metriura with Fufius, Fufius striatipes (Drolshagen & Backstam, 2009) comb. nov. is established.

Azilia leucostigma Mello-Leitao 1941 considered by Mello-Leitao as a metine (Tetragnathidae), is transferred to the gnaphosoid family Gallieniellidae, as the type species of the new genus Galianoella. The obliquely depressed endites, the flattened irregular posterior median eyes, and the conical anterior lateral spinnerets retaining a sclerotized distal ring, among other characters, clearly place the new genus in the family Gallieniellidae. Galianoella leucostigma is the only gallieniellid so far recorded from the Americas. This species has a specialized ant-preying behavior. Ant-preying may prove to be characteristic for all the family, as it was suspected in the Madagascan Gallieniella; and it may be associated with the modified chelicerae typical of the family.

The Central American hunting spider Cupiennius salei Keys relies mainly on its mechanosensory systems during prey-catching and mating behaviour. The behavioural relevance of its eight eyes has not been studied before, although their optics and sensitivity suggest highly developed visual capabilities. The visual system was examined in a twofold simultaneous-choice experiment. Two targets were presented at a distance of 2 m from the animals, and their walking paths towards the targets were monitored. Spiders showed no preference when choosing between two identical targets, but when choosing between two different targets they strongly preferred a vertical bar to a sloping bar or a V-shaped target. By covering all eyes except the anterior median or posterior median eyes, it could be shown that the spiders were able to detect the targets using any of the eyes. Discrimination between different targets was only possible with the anterior median eyes uncovered, although the visual fields of the anterior median and posterior median eyes overlap completely. It seems most likely that the animals separate visual information in the periphery and therefore that the eyes have different functions. The posterior median eyes support a target-detecting mechanism and the anterior median eyes a target-discrimination mechanism.

(クモ 目:ハ エ トリグモ科) Abstract A new salticid spider species, Laufeia sasakii sp. nov . is described on the basis of the materials obtained from Tokunoshima Island, Kagoshima Pref., Japan. Another species of the same genus, Laufeia aenea Simon, 1889, is redescribed . Simon (1889) described six new species of spiders based on the specimens collected by Mellottee from Yokohama City, Kanagawa Pref., Japan, and established three new genera, Laufeia, Siler and Tricca. The former two genera belong to salticid spiders, and the last genus belong to lycosid spiders. Up to the present, six species of the genus Laufeia were described in the world (Proszyflski 1990). However, some of them may be not congeneric, and hence further study is necessary (Zabka 1985, Bohdanowicz and Proszyflski 1987). When I examined the spider specimens collected by Takeshi Sasaki from Tokuno- shima Island, Kagoshima Pref., Japan, I recognized a new species of the genus Laufeia in the specimens. The species resembles Laufeia aenea Simon , 1889, however the previous description of the latter species was not adequate for some errors such as leg length (Simon 1889), male palps (Yaginuma 1986, Bohdanowicz and Proszyflski 1987). These two species will be described in the present paper. The type specimens designated in this paper are deposited in the collection of the Department of Zoology, National Science Museum (Nat. Hist.), Tokyo. The following abbreviations are used: ALE, anterior lateral eye; AME , anterior median eye; PLE, posterior lateral eye; PME, posterior median eye. The distances between eyes are presented with a dash, e.g., ALE-ALE indicates distance between ALEs.

We studied fine structural correlates of sensitivity in the principal and secondary eyes of the nocturnal hunting spider Cupiennius salei. In night-adapted eyes the four rhabdomeres of the principal eye photoreceptors are 58 microm long and occupy together 234 microm(2) in cross-section (average), whereas the two rhabdomeres of the secondary eye photoreceptors are about 49 microm long and measure 135-183 microm(2) in cross-section (average). The rhabdoms (photosensitive structures) consist of tightly packed microvilli (diameter 0.1 microm, maximum length 3.5 microm) and occupy up to 63% of the cross-sectional area of the retina. When calculating the amount of light the eyes of Cupiennius are able to capture according to their morphological characteristics, the values for sensitivity S(see Land, 1981, 1985) are between 78 and 109 microm(2). Cupiennius is more sensitive than any other hunting spider examined except Dinopis whose posterior median eyes are the most sensitive ones of all terrestrial arthropod eyes studied. In day-adapted eyes the rhabdomeral microvilli are almost completely degraded. The remaining microvillar surface amounts to only about one-tenth compared with the night-adapted state. Efferent synaptoid terminals have been found to contact the photoreceptors in all eyes of C. salei. The present fine structural data are compared to previous electrophysiological research and underline the significance of vision in Cupiennius.

Local sensitivity for certain density bounded class of priors are considered. We give an exact form of the local sensitivity of the posterior mean and the posterior median, and also investigate the behavior of these local sensitivity measures for varying values of data in a specific example.

Intracellular recordings from photoreceptor cells of all eyes of the spider Cupiennius salei Keys reveal 3 groups of cells with spectral sensitivity maxima in the blue (480 nm). green (520 nm), and UV (340 nm), respectively. The blue and green cells show secondary peaks in the UV at 340-380 nm. In the posterior median, posterior lateral and anterior median eyes, the majority of photoreceptor cells are the blue and green cells in roughly equal numbers. In the anterior lateral eye, however, the green cells dominate. UV cells were only found in the secondary eyes and only once in each of them.

Testing of composite fecal (environmental) samples from high traffic areas in dairy herds has been shown to be a cost-effective and sensitive method for classification of herd status for Mycobacterium avium subsp. paratuberculosis (MAP). In the National Animal Health Monitoring System's (NAHMS) Dairy 2007 study, the apparent herd-level prevalence of MAP was 70.4% (369/524 had ≥1 culture-positive composite fecal samples out of 6 tested). Based on these data, the true herd-level prevalence (HP) of MAP infection was estimated using Bayesian methods adjusting for the herd sensitivity (HSe) and herd specificity (HSp) of the test method. The Bayesian prior for HSe of composite fecal cultures was based on data from the NAHMS Dairy 2002 study and the prior for HSp was based on expert opinion. The posterior median HP (base model) was 91.1% (95% probability interval, 81.6 to 99.3%) and estimates were most sensitive to the prior for HSe. The HP was higher than estimated from the NAHMS Dairy 1996 and 2002 studies but estimates are not directly comparable with those of prior NAHMS studies because of the different testing methods and criteria used for herd classification.

A new genus and species, Iraponia scutata, are established for the first members of the Caponiidae to be found in Iran. Males of this new genus, the second known from Asia, are unique in the family in having an extensive ventral abdominal scutum, and in having lost the posterior median pair of spinnerets. These caponiids have six eyes, a character shared only with some members of the New World genus Caponina.

The present article brings in the notion of Posterior Pitman Closeness (PPC) in contrast to the usual Pitman Closeness (PC) criterion. Unlike the PC criterion, the PPC criterion does not suffer from lack of transitivity. Also, a posterior median is usually a posterior Pitman closest estimator of the parameter of interest. Examples are provided to illustrate these ideas. Also, some multivariate analogs of these results are presented.

Efferent impulses in the optic nerves of the orb weaving spiders Argiope amoena and A. bruennichii in response to illumination of single eyes were examined. When light stimulation was given to the anterior median (AM) eye, the frequency of efferent optic nerve impulses increased transiently only after the offset of illumination. In contrast, when the light was given to the anterior lateral (AL), posterior median (PM) or posterior lateral (PL) eye, the frequency of efferent impulses increased transiently both after the onset and after the offset of illumination. It is suggested that the impulse generation after the onset of illumination is caused by a gradual decrease in magnitude of depolarizing photoreceptor potentials in the AL, PL and PM eyes.

Cryptocellus tarsilae n. sp. is described from male and female specimens collected in a small cave at Carajás National Forest, Serra Norte, Pará, Brazil. The new species appears to be similar to C. peckorum Platnick & Shadab, 1977 by the moderately expanded metatarsus III, bearing a metatarsal process with a flattened tip. Both males and females of the new species are readily recognizable by the carapace having a posterior median bulge covered by tubercles.

The paucity of photons at night poses special problems for small nocturnal ambush predators, at least if vision is the principal sensory modality. All spiders are carnivores and must snare their prey with stealth or traps. Most arachnid predators that rely on vision and stealth, such as salticids ( British Journal of Ophthalmology , March 2006), are almost exclusively diurnal. These spiders have evolved large, anterior median eyes among their four sets of eyes. But, sharp-eyed nocturnal arachnid predators, such as the lycosids ( British Journal of Ophthalmology , November 2002), have evolved large posterior median eyes, but why the difference? Deinopis subrufa has an interesting lifestyle, as the common name, net-casting spider, suggests. Spread through the remnants of the ancient Gondwanaland, D subrufa spins a cribellate (a sticky form of silk different from that spun by orbweavers) web and uses it as a trap. The spider holds the web with four of its eight legs and hides under vegetation. She will often dangle, head down, under a leaf, her long body and legs resembling a stick. She will hang just above ground level and prepare the trap. From that position, she will defecate …

The African spider Cithaeron reimoseri Platnick, 1991 is registered for the first time in the New World, based in two females collected at Porto Alegre, Rio Grande do Sul, Brazil. Until now C. reimoseri was known only by the holotype from Eritrea. The species C. praedonius O. P.-Cambridge, 1872 was, until now, the only known species of the family with worldwide distribution and is considered prone to introduction in anthropic environments. Cithaeronidae are considered lower gnaphosoids being identifiable by the depressed posterior median eyes and the pseudosegmented tarsi.

Motivated by the first-order Pitman closeness of best asymptotically normal estimators and some recent developments on higher-order asymptotic efficiency of estimators, a second-order asymptotic theory is developed for comparison of estimators under the Pitman closeness criterion, covering both the cases without and with nuisance parameters. The notion of second-order Pitman admissibility is also developed.

A model is given for a class of contests in which the participants try to guess (or estimate) unknown quantities, and the objective of each player is to come closer to the unknown quantities than an adversary. A general optimality result is proved that gives the best guessing rules for the second guesser. These rules are first calculated exactly in a certain hierarchical linear model, and then simpler approximate rules are given.

Interneurones in the median posterior protecerebrum of the honeybee were analysed using intracellular recording and staining. Their responses to stimulation of ocelli and compound eyes were studied. The interneurones recorded can be divided into two groups on the basis of their anatomy. These are: (A) Interneurones associated with ocellar terminals, optic commissures and tracts originating from the medulla and lobula of the compound eyes; (B) Interneurones belonging to the central complex. The light responses are generally complex, differing from neurone to neurone. However, many of the recorded interneurones from group A exhibit antagonistic ocelli-compound eye responses. Responses to ocellar illumination in group B neurones demonstrate that some input to the central complex originates from the ocelli. The results are discussed with respect to the interactions between ocellus and compound eye, and the representation of ocellar information within certain brain regions.

Populations are compared of the E. Australian net-casting spiders Dinopis subrufus (L. Koch 1878) and Menneus unifasciatus (L. Koch 1878) co-existing in dry sclerophyll forest. Previous recent accounts of net-building by Dinopis are confirmed, and it is shown that Menneus constructs its snare in essentially the same way. Whereas Dinopis makes its net in relation to horizontal surfaces and catches prey walking across them, Menneus relates it to vertical grass-stems and twigs near to the ground, and catches small blattellid cockroaches which run up them (92 % of prey records). Prey-capture by Dinopis appears to be non-selective, and includes cockroaches (23%), ants (33%) and other spiders (15%). Both genera are nocturnal and are procryptic by day. Dinopis become active after nightfall, Menneus during twilight. The time taken for net-construction nevertheless means that both must capture the bulk of their prey after dark. It is suggested that the large posterior median eyes of Dinopis, known to be highly specialized for night-vision, are used to discriminate prey whose reflectances differ little from those of their backgrounds. It is possible that Menneus locates prey through vibration of the framework of the snare, but the small, unspecialized eyes may perceive prey insects as silhouettes against much lighter surrounds because of the orientation of the snare and the nature of the background.

Wolf spiders have four pairs of eyes distributed in three rows. The first row which lie in the frontal region of the caparace, just above the chelicera, contains four eyes: a medial pair known as the anterior medial eyes (AM eyes or principal eyes) and two smaller eyes known as the anterior lateral eyes (AL eyes). The second row which is located also in the frontal region of the prosoma consists of two big eyes. These are the posterior median eyes (PM eyes). The third row contains the posterior lateral eyes (PL eyes) which lie in the flanks of the prosomal caparace. The AL, PM and PL eyes are the so-called secondary eyes.