Intra-Areal Visual Topography in Primate Brains Mapped with Probabilistic Tractography of Diffusion-Weighted Imaging.

Noninvasive diffusion-weighted magnetic resonance imaging (dMRI) can be used to map the neural connectivity between distinct areas in the intact brain, but the standard resolution achieved fundamentally limits the sensitivity of such maps. We investigated the sensitivity and specificity of high-resolution postmortem dMRI and probabilistic tractography in rhesus macaque brains to produce retinotopic maps of the lateral geniculate nucleus (LGN) and extrastriate cortical visual area V5/MT based on their topographic connections with the previously established functional retinotopic map of primary visual cortex (V1). We also replicated the differential connectivity of magnocellular and parvocellular LGN compartments with V1 across visual field positions. Predicted topographic maps based on dMRI data largely matched the established retinotopy of both LGN and V5/MT. Furthermore, tractography based on in vivo dMRI data from the same macaque brains acquired at standard field strength (3T) yielded comparable topographic maps in many cases. We conclude that tractography based on dMRI is sensitive enough to reveal the intrinsic organization of ordered connections between topographically organized neural structures and their resultant functional organization.

Acoustic shock: an update review.

BACKGROUND: This paper discusses the concept of acoustic shock based on a literature review and the results of our own research into cases seen in both clinical and medicolegal practice. With the demise of traditional 'metal bashing' and 'smoke stack' heavy industries, there has been a decline in the incidence of noise-induced hearing loss and tinnitus in this form of employment. However, with the increasing establishment of call centre work, the emergence of acoustic shock has been noted. Acoustic shock is recognised as a clinical entity distinct from noise-induced hearing loss and acoustic trauma. OBJECTIVE: This article discusses clinical implications, medicolegal considerations in light of a recent high-profile court case and proposed criteria for diagnosis.

Short communication: pharmacokinetics of oxytocin administered intranasally to beef cattle.

Providing the neuropeptides oxytocin and vasopressin intranasally increased concentrations in plasma and cerebral spinal fluid in humans and primates, respectively. This is of interest because of the documented anxiolytic effects of oxytocin observed in humans and rodents. To date, a transnasal approach of hormone administration has not been investigated in beef cattle. Defining the pharmacokinetics of intranasal oxytocin in cattle is necessary for determining optimum sampling and dosing timelines for future investigations. Five, weaned Bos taurus steers were used in a 3 × 3 Latin square design. Treatments included 1) 0.33 IU oxytocin/kg BW (A, n = 5), 2) 0.66 IU oxytocin/kg BW (B, n = 5), and 3) 1.32 IU oxytocin/kg BW (C, n = 5). Steers were acclimated to handling and restraint procedures for 4 wk leading up to the start of the experiment. Frequent blood collection occurred every 2 min for the first 30 min and every 5 min for the second 30 min, relative to administration of intranasal treatment. No treatment by time interaction was detected; however, there was an effect of time (P < 0.001) and treatment (P = 0.002) on oxytocin concentrations over time. Pharmacokinetic parameters, determined by PKSolver excel add-in, demonstrated an average maximum concentration (CMAX) of 63.3 pg/mL at 3.5 min after intranasal dose administration. An average half-life (T1/2) of 12.1 min after intranasal administration was determined. Pharmacokinetic parameters to a single bolus were not dose-dependent.

Intranasal oxytocin treatment does not attenuate the hypothalamo-pituitary-adrenal axis in beef heifers subjected to isolation stress or restraint and isolation stress.

Changes in the physiological, psychological, and behavioral manifestations of stress have been observed in association with increases in circulating oxytocin (OXT). Providing OXT intranasally has been shown to attenuate stressor-induced hypothalamo-pituitary-adrenal (HPA) axis activation in humans and rodents; however, anxiolytic effects may be context and species specific. The present study aimed to investigate the effect of intranasal OXT supplementation on stressor-induced activation of the HPA axis in beef cattle. We hypothesized that OXT would attenuate activation of the HPA axis, ultimately decreasing plasma cortisol and adrenocorticotropic hormone (ACTH). Twenty-eight Bos taurus heifers were blocked by bodyweight and randomly allocated to one of four treatment groups, in a 2 × 2 factorial arrangement: (1) saline, isolated, standing, and unrestrained (S-isolation stress [IS], 0.015 mL/kg BW 0.9% isotonic saline, n = 7); (2) saline, isolated, and restrained (S-restraint and isolation stress [RIS]; 0.015 mL/kg BW 0.9% isotonic saline; n = 7); (3) OXT, IS (OXT-IS, 0.3 IU/kg BW oxytocin; n = 7); and (4) OXT and RIS (OXT-RIS, 0.3 IU/kg BW oxytocin; n = 7). Oxytocin and saline were administered intranasally. Intranasal treatments were given followed by a waiting time of 30 min when each of the stress treatments was applied for 2 h. Blood samples were collected via jugular catheters directly after stressor application and every 10 min thereafter, for 2 h. Cortisol concentrations increased over time in animals exposed to RIS (P < 0.01) and decreased over time in animals exposed to IS (P < 0.01). Concentrations of ACTH decreased over time for the IS-treated heifers but remained elevated for the RIS-treated heifers (P < 0.01). Under the conditions of the present study, OXT treatment did not affect measured indicators of HPA axis activation. A treatment × time interaction (P < 0.01) was detected for OXT, such that OXT heifers exhibited greater initial OXT concentrations followed by a decline; saline-treated heifers had consistently stable oxytocin concentrations. The RIS-treated heifers increased their glucose (P < 0.01) and lactate (P < 0.01) concentrations throughout the application of the stressors compared with the IS-treated heifers. Overall, restraint stress increased cortisol and oxytocin in B taurus heifers compared with heifers subjected only to isolation. Finding a more intermediate stress model may better allow for detection of the effects of oxytocin on the stress response.

Interneuronal correlations at longer time scales predict decision signals for bistable structure-from-motion perception.

Perceptual decisions are thought to depend on the activation of task-relevant neurons, whose activity is often correlated in time. Here, we examined how the temporal structure of shared variability in neuronal firing relates to perceptual choices. We recorded stimulus-selective neurons from visual area V5/MT while two monkeys (Macaca mulatta) made perceptual decisions about the rotation direction of structure-from-motion cylinders. Interneuronal correlations for a perceptually ambiguous cylinder stimulus were significantly higher than those for unambiguous cylinders or for random 2D motion during passive viewing. Much of the difference arose from correlations at relatively long timescales (hundreds of milliseconds). Choice-related neural activity (quantified as choice probability; CP) for ambiguous cylinders was positively correlated with interneuronal correlations and was specifically associated with their long timescale component. Furthermore, the slope of the long timescale - but not the instantaneous - component of the correlation predicted higher CPs towards the end of the trial i.e. close to the decision. Our results suggest that the perceptual stability of structure-from-motion cylinders may be controlled by enhanced interneuronal correlations on longer timescales. We propose this as a potential signature of top-down influences onto V5/MT processing that shape and stabilize the appearance of 3D-motion percepts.

Nanoinformatics, and the big challenges for the science of small things.

The combination of computational chemistry and computational materials science with machine learning and artificial intelligence provides a powerful way of relating structural features of nanomaterials with functional properties. However, combining these fundamentally different scientific approaches is not as straightforward as it seems. Machine learning methods were developed for large data sets with small numbers of consistent features. Typically nanomaterials data sets are small, with high dimensionality and high variance in the feature space, and suffer from numerous destructive biases. None of the established data science or machine learning methods in widespread use today were devised with (nano)materials data sets in mind, but there are ways to overcome these challenges and use them reliably. In this review we will discuss domain-specific constraints on data-driven nanomaterials design, and explore the differences between nanomaterials simulation and nanoinformatics that can be leveraged for greater impact.

Salmonella monitoring programs in Australian feed mills: a retrospective analysis.

The availability of safe, commercially prepared stock feed for production animals is an important step in ensuring animal health and welfare and the safety of food animal products for human consumption. Animal feed quality assurance programs include microbiological monitoring of raw materials, mill equipment and finished feed. Over a period of 16 years, 23,963 samples for Salmonella culture and serotyping were collected from 22 stock feed mills. A multivariable generalized linear mixed model (GLMM) was used to identify mill and sample type factors that increase the odds of detecting Salmonella. The odds of detecting a Salmonella positive sample was greatest in samples from raw materials and in mills that processed restricted animal material (RAM). The percentage of positive samples ranged from 7.2% in 2003 to 2.8% in 2017. Of the 1,069 positive samples, 976 were serotyped with 61 different Salmonella serotypes isolated. The serotype most frequently isolated from raw materials was S. Agona, (n = 108) whilst S. Anatum was the serotype most frequently isolated from equipment and finished feed (n = 156). The diversity of Salmonella serotypes differed between mills and different stages of the production line. Microbiological monitoring in the commercial preparation of animal feed in Australian stock feed mills guides the implementation of quality control measures and risk mitigation strategies thereby reducing the prevalence and diversity of potentially zoonotic bacteria such as Salmonella, enhancing food safety for both animal and consumer.

Feed and water deprivation has a negative but transient effect on the rumen kinetics of Bos indicus steers.

The effects on rumen kinetics after feed and water had been deprived for 72 hr were studied using four fistulated Bos indicus steers. The animals were assigned in a 2 × 4 crossover design with two treatments: feed and water ad libitum (control) and no feed and water for 72 hr (deprived) with four steers per treatment over two time periods. Feed and water deprivation caused decreases in the numbers of cellulolytic bacteria (1.4 vs. 0.4 cfu × 106 /ml; p = .001), live (23.7 vs. 0.8 × 109 /ml; p = .001), dead (12.7 vs. 0.5 × 109 /ml; p = .001) and total bacterial counts (36.4 vs. 1.4 × 109 /ml; p = .001) at day 0, compared with the control treatment. However, the deprived group had greater numbers of cellulolytic bacteria (2.7 vs. 50.1 cfu × 106 /ml; p = .001), live (18.3 vs. 42.2 × 109 /ml; p = .001), dead (6. 5 vs. 19.1 × 109 /ml; p = .001) and total bacterial counts (24.8 vs. 61.3 × 109 /ml; p = .001) from rumen fluid on day 4, compared with the control treatment. The numbers of protozoa in rumen fluid from the deprived group were less than (551.2 vs. 2.4 × 103 /ml; p = .001) the control group on day 0. However, the deprived treatment had fewer protozoa in rumen fluid than the control treatment on day 4 (p = .001) and day 9 (p = .001). Volatile fatty acids and in vitro gas production as functional measurements of rumen fluid followed the same trend as the bacterial and protozoa populations. These results indicate that feed and water deprivation would have a negative but transient effect on the rumen kinetics of Bos indicus steers.

Hypovitaminosis A in extensively grazed beef cattle.

CASE REPORT: Vitamin A deficiency was diagnosed in a herd of 97 19-month-old Braford heifers in the Mitchell Grass Downs (Astrebla spp.) bioregion of Hughenden in north-western Queensland during November 2015. Two heifers died after a 48-h history of sternal recumbency and of the 19 that had neurological signs, 7 were blind. Histological changes in the optic nerves of the two necropsied cattle were consistent with vitamin A deficiency. This diagnosis was supported by vitamin A concentrations in fresh liver samples of 5 and 6 mg/kg wet tissue (reference range, 100-175 mg/kg) despite treatment of the cattle with twice the recommended dose of parenteral vitamin A 3 weeks prior to sampling. Rainfall on the property during the 2 years before the outbreak was less than the annual rainfall average of 464 mm, with a total of 281 mm in 2014 and 117 mm from January to November in 2015, most of this falling in January. CONCLUSION: Plant assays for both ß-carotene and crude protein concentrations in dry matter (DM) were less than the recommended dietary requirements for beef cattle (0.30 mg/kg DM and 56 g/kg, respectively).

Individual Differences in the Alignment of Structural and Functional Markers of the V5/MT Complex in Primates.

Extrastriate visual area V5/MT in primates is defined both structurally by myeloarchitecture and functionally by distinct responses to visual motion. Myelination is directly identifiable from postmortem histology but also indirectly by image contrast with structural magnetic resonance imaging (sMRI). First, we compared the identification of V5/MT using both sMRI and histology in Rhesus macaques. A section-by-section comparison of histological slices with in vivo and postmortem sMRI for the same block of cortical tissue showed precise correspondence in localizing heavy myelination for V5/MT and neighboring MST. Thus, sMRI in macaques accurately locates histologically defined myelin within areas known to be motion selective. Second, we investigated the functionally homologous human motion complex (hMT+) using high-resolution in vivo imaging. Humans showed considerable intersubject variability in hMT+ location, when defined with myelin-weighted sMRI signals to reveal structure. When comparing sMRI markers to functional MRI in response to moving stimuli, a region of high myelin signal was generally located within the hMT+ complex. However, there were considerable differences in the alignment of structural and functional markers between individuals. Our results suggest that variation in area identification for hMT+ based on structural and functional markers reflects individual differences in human regional brain architecture.

Effect of hormonal synchronisation and/or short-term supplementation with maize on follicular dynamics and hormone profiles in goats during the non-breeding season.

This study aimed to evaluate the reproductive response of anoestrous goats that were either hormonally treated and/or supplemented with maize for 9days to determine which treatment combination was the most effective in enhancing follicular development and ovulation rate, and whether these responses were associated with increases in metabolic hormones. The experiment was carried out using 28 does, using a 2×2 factorial design with seven does in each group to test the effect of synchronisation of oestrus, supplementation with maize and their interactions. Synchronisation of oestrous cycles (P<0.001) but not supplementation with maize or the interaction between the two (P>0.05) increased the number of codominant follicles, the diameter of the largest follicle on Day 9 and growth rate of follicles during the period of supplementation. Compared with non-supplemented animals, supplementation with maize increased the total number of follicles observed between Days 7 and 9 (P=0.039). In addition, nutritional supplementation with maize in combination with synchronisation of oestrus increased the ovulation rate by 43% (P=0.074). Interactions between time and supplementation with maize showed that plasma concentrations of insulin, leptin and IGF-1 were greater in does supplemented with maize compared with non-supplemented does (P<0.001). The findings show that hormonal synchronisation had the most influence on modifying follicular development and ovulation in anoestrous goats. Supplementation with maize increased the concentrations of insulin, leptin and IGF-1, which could potentially modify the sensitivity of follicles to gonadotrophins and reduce rates of atresia.

Bos indicus cattle possess greater basal concentrations of HSP27, alpha B-crystallin, and HSP70 in skeletal muscle in vivo compared with cattle.

The objectives of the present study were to evaluate the basal concentrations of heat shock proteins (HSP) between and cattle and to determine if HSP basal concentrations change as an animal matures. A total of 40 cattle were used in a 2 × 2 factorial design to evaluate the effects of genotype and age (heifers and mature cows) on basal concentrations of heat shock protein 27 (HSP27), α B-crystallin (Cryab), and heat shock protein 70 (HSP70). Each experimental group of 10 animals was sampled on a separate day over a period of 4 wk during July 2014. A muscle sample was collected from the longissimus thoracis (LT) and concentrations of HSP were quantified using ELISA. There were no significant differences in HSP concentration for the interaction between age and genotype or for age alone. cattle had greater ( < 0.05) basal concentrations of HSP27, Cryab, and HSP70 in the LT than cattle. The results of this study show that basal in vivo HSP concentrations differ between and cattle. However, further studies are needed to investigate the relationship between HSP concentrations and meat tenderness with respect to genotypes to see if HSP concentrations account for at least some variability in tenderness differences.

A pilot study to evaluate assisted freehand ultrasound elasticity imaging in the sizing of early breast cancer: a comparison of B-mode and AFUSON elasticity ultrasound with histopathology measurements.

OBJECTIVE: This pilot study investigates the role of assisted-freehand ultrasound (AFUSON) elasticity imaging of the breast in assessing the contour, size and area of 23 early breast cancers by making comparison of AFUSON with the equivalent B-mode ultrasound images and gold standard histopathology slides. METHODS: The B-mode, AFUSON and digitised histopathology slides of three early breast cancers were compared for contour, size and area with histopathology scans. AFUSON features that corresponded to areas of known malignant change on the histopathology slides were regarded as diagnostic. These diagnostic criteria were then applied to the B-mode and AFUSON elasticity images of all 23 breast cancers in the pilot study without having the availability of the histopathology scans for reference. Corresponding diameters were measured and the results were compared with the equivalent measurements on the scans of the histology slides. The results were tabulated in histogram form. Diagnostic confidence levels were evaluated. RESULTS: Size dimension accuracy increased from 66% using B-mode alone to 82% using combined B-mode and AFUSON elasticity images. Tumour area accuracy was also increased. A small number of cases had a striking visual similarity of shape on AFUSON elasticity scans and histopathology slides. CONCLUSION: In spite of the shortfalls in this study, AFUSON elasticity imaging was capable of acquiring some high-quality images that showed strong correlation between AFUSON elasticity and scans of histology slides. Further studies will be carried out to refine the technique and determine if it has a role in the diagnosis and management of breast cancer.

Strychnine poisoning: gone but not forgotten.

Strychnine was used as a pesticide until 1968 and a rodenticide until 2006 when its sale was banned throughout the EU and all supplies recalled. A case of strychnine poisoning seen in a UK emergency department in 2009 is reported to remind clinicians of the features and management of this increasingly rare presentation. Prompt recognition and early intensive supportive therapy can result in a favourable outcome.

In vitro-in vivo extrapolation of hepatic clearance involving active uptake: theoretical and experimental aspects.

The importance of hepatic uptake transporters in drug clearance is well recognized. The subject is reviewed with the intention of providing an overview of the concepts in order to link the increasing knowledge of transporter-mediated uptake into established models of hepatic clearance. In order to understand and quantify their impact, models of hepatic elimination that incorporate permeability barriers are required. Models that include both active and passive uptake into hepatocytes are discussed and simulations of the influence of active uptake and passive diffusion on hepatic clearance are presented. The advantages and weaknesses of a number of in vitro assays of hepatic uptake are described, and their ability to predict hepatic clearance is reviewed.

Physiological and metabolic effects of prophylactic treatment with the osmolytes glycerol and betaine on Bos indicus steers during long duration transportation.

The physiological and metabolic effects of prophylactic treatment with osmolytes were investigated using twenty-four 2.5-yr-old Bos indicus steers. Animals were allocated to 1 of 4 treatment groups: 1) control, feed and water deprived for 48 h (n = 6); 2) transported, transported for 48 h (n = 6); 3) glycerol, dosed with glycerol (2 g/kg of BW) and then transported for 48 h (n = 6); and 4) betaine, dosed with betaine (0.25 g/kg of BW) then transported for 48 h (n = 6). Body water, electrolytes, blood pH and gases, plasma lactate, glucose, albumin, total protein, anion gap, strong ion difference, total weak acids, and BW were determined at the conclusion of 24 and 48 h of transportation. The glycerol group had greater body water volumes than the control (P = 0.05) and transported (P = 0.02) groups. The glycerol, transported, and betaine groups had lower (P = 0.02) plasma Mg concentrations than the control group at 24 h, whereas the glycerol group maintained lower (P = 0.04) plasma concentrations of Ca than the control group. The betaine group had lower (P = 0.04) hematocrit than the control group at 24 and 48 h. Plasma bicarbonate and pCO2 were 13 and 17% greater (P = 0.01 and 0.04, respectively) in the glycerol group at 24 h compared with control and transported groups. However, the ratio of [HCO3]/[CO2] in the glycerol group did not differ from the other groups and thereby maintained pH. The glycerol group maintained a 30% greater (P < 0.001) plasma concentration of glucose than the control group, and 14% greater (P = 0.05) than the transported and betaine groups. In contrast, betaine had little effect on increasing blood glucose compared with glycerol. Glycerol-linked hyperhydration at 24 h may not only help to conserve water loss during long distance transportation, but the increased blood glucose may have an important protein-sparing effect due, in part, to greater insulin concentrations inhibiting the breakdown of muscle proteins, thus, countering the amino-acid mobilizing effect of cortisol after 24 h. Therefore, the osmolyte glycerol shows promise as a prophylactic treatment for attenuating the effects of long distance transportation by maintaining body water, decreasing the energy deficit, and preserving health and muscle quality.

Radiological review of specimen radiographs after breast localisation biopsy is not always necessary.

INTRODUCTION: The use of specimen radiographs to confirm the presence of the radiological abnormality in a breast specimen after localisation biopsy is standard practice. This study aims to show that a trained surgeon may assess breast specimen radiographs with similar efficacy as a radiologist. METHODS: This retrospective study assessed all patients who had localisation breast surgery using wire or ultrasound (US) techniques between January 2002 and March 2003. Histopathological records and mammographic details were recorded from the hospital notes. A consultant radiologist and surgeon reviewed the specimen radiographs, identifying mammographic abnormalities and assessing margins. RESULTS: Localisation surgery was performed on 101 patients with US used to localize 68. The median specimen weight was 64g. A malignant diagnosis was made in 86 patients. In 23, the histological resection margins were considered to be close or involved by tumour and re-excision was performed in eight patients. Sixty-one specimen radiographs were reviewed. The radiologist identified every mammographic abnormality, and the surgeon identified the lesion in 58. The positive predictive value of specimen radiographs to identify histologically involved margins was 75 and 74% by the radiologist and the surgeon, respectively. Where good radiograph margins were reported in 40 and 35 patients by the radiologist and surgeon, respectively, 11 and 7 had histologically involved margins. CONCLUSIONS: This study shows that a suitably trained or experienced surgeon can assess specimen radiographs effectively without the need for intraoperative radiological input although complete histological resection is not guaranteed despite specimen radiographs demonstrating clear margins.

Near fatal haemorrhage 35 years after radiation for laryngeal cancer: emergency embolisation of a vertebral artery aneurysm.

The authors report a rare case of a 75 year old man who presented 35 years after radiotherapy for carcinoma of the larynx, with catastrophic bleeding through the mouth. Both the time and mode of presentation were unusual. The patient required emergency sacrifice of the left vertebral artery to stop the bleeding. The literature has been reviewed.