Cerebellum and neurodegenerative diseases: Beyond conventional magnetic resonance imaging

The cerebellum plays a key role in movement control and in cognition and cerebellar involvement is described in several neurodegenerative diseases. While conventional magnetic resonance imaging (MRI) is widely used for brain and cerebellar morphologic evaluation, advanced MRI techniques allow the investigation of cerebellar microstructural and functional characteristics. Volumetry, voxel-based morphometry, diffusion MRI based fiber tractography, resting state and task related functional MRI, perfusion, and proton MR spectroscopy are among the most common techniques applied to the study of cerebellum. In the present review, after providing a brief description of each technique's advantages and limitations, we focus on their application to the study of cerebellar injury in major neurodegenerative diseases, such as multiple sclerosis, Parkinson's and Alzheimer's disease and hereditary ataxia. A brief introduction to the pathological substrate of cerebellar involvement is provided for each disease, followed by the review of MRI studies exploring structural and functional cerebellar abnormalities and by a discussion of the clinical relevance of MRI measures of cerebellar damage in terms of both clinical status and cognitive performance

Picky eaters are rare: DNA-based blood meal analysis of \u3ci\u3eCulicoides\u3c/i\u3e (Diptera: Ceratopogonidae) species from the United States

Background: Biting midges in the genus Culicoides (Diptera; Ceratopogonidae) have been implicated in the transmission of a number of parasites and highly pathogenic viruses. In North America, the complete transmission cycles of many of these pathogens need further elucidation. One way to increase our knowledge about the evolution and ecology of Culicoides species and the pathogens they transmit is to document the diversity of vertebrate hosts that Culicoides feed upon. Our objective was to identify the diversity of Culicoides hosts in the United States. Results: We sequenced two vertebrate mitochondrial genes (cytochrome c oxidase subunit 1 and cytochrome b) from blood-engorged Culicoides to identify Culicoides species and their blood meals. We detected the mitochondrial DNA of 12 host species from seven different Culicoides species from three states. The majority of the identified blood meals were from the C. variipennis species complex in California. The hosts included both mammals and birds. We documented new host records for some of the Culicoides species collected. The majority of the mammalian hosts were large ungulate species but we also detected a lagomorph and a carnivore. The bird species that were detected included house finch and emu; the latter is evidence that the species in the C. variipennis species complex are not strictly mammalophilic. Conclusions: These results demonstrate that Culicoides will feed on multiple classes of vertebrates and may be more opportunistic in regards to host choice than previously thought. This knowledge can help with identification of susceptible host species, pathogen reservoirs, and new vector species which, in turn, will improve disease outbreak risk assessments

A MATLAB app to assess, compare and validate new methods against their benchmarks

Emerging technologies for physiological signals and data collection enable the monitoring of patient health and well-being in real-life settings. This requires novel methods and tools to compare the validity of this kind of information with that acquired in controlled environments using more costly and sophisticated technologies. In this paper, we describe a method and a MATLAB tool that relies on a standard sequence of statistical tests to compare features obtained using novel techniques with those acquired by means of benchmark procedures. After introducing the key steps of the proposed statistical analysis method, this paper describes its implementation in a MATLAB app, developed to support researchers in testing the extent to which a set of features, captured with a new methodology, can be considered a valid surrogate of that acquired employing gold standard techniques. An example of the application of the tool is provided in order to validate the method and illustrate the graphical user interface (GUI). The app development in MATLAB aims to improve its accessibility, foster its rapid adoption among the scientific community and its scalability into wider MATLAB tools

Can demographic histories explain long-term isolation and recent pulses of asymmetric gene flow between highly divergent grey fox lineages?

Secondary contact zones between deeply divergent, yet interfertile, lineages provide windows into the speciation process. North American grey foxes (Urocyon cinereoargenteus) are divided into western and eastern lineages that diverged approximately 1 million years ago. These ancient lineages currently hybridize in a relatively narrow zone of contact in the southern Great Plains, a pattern more commonly observed in smaller-bodied taxa, which suggests relatively recent contact after a long period of allopatry. Based on local ancestry inference with whole-genome sequencing (n = 43), we identified two distinct Holocene pulses of admixture. The older pulse (500–3500 YBP) reflected unidirectional gene flow from east to west, whereas the more recent pulse (70–200 YBP) of admixture was bi-directional. Augmented with genotyping-by-sequencing data from 216 additional foxes, demographic analyses indicated that the eastern lineage declined precipitously after divergence, remaining small throughout most of the late Pleistocene, and expanding only during the Holocene. Genetic diversity in the eastern lineage was highest in the southeast and lowest near the contact zone, consistent with a westward expansion. Concordantly, distribution modelling indicated that during their isolation, the most suitable habitat occurred far east of today\u27s contact zone or west of the Great Plains. Thus, long-term isolation was likely caused by the small, distant location of the eastern refugium, with recent contact reflecting a large increase in suitable habitat and corresponding demographic expansion from the eastern refugium. Ultimately, long-term isolation in grey foxes may reflect their specialized bio-climatic niche. This system presents an opportunity for future investigation of potential pre- and post-zygotic isolating mechanisms

A molecular analysis to assess codling moth \u3ci\u3eCydia pomonella\u3c/i\u3e L. (Lepidoptera: Tortricidae) predation by orchard birds

The codling moth Cydia pomonella L. (Lepidoptera: Tortricidae) is a major economic pest in organic apple orchards. Observational methods, prey removal experiments and correlative experiments with exclosures or nest boxes have demonstrated that birds contribute to the removal of this insect pest. However, the majority of research conducted in the last several decades has taken place outside of the United States and methods for studying biological pest control have advanced dramatically and now include molecular techniques. We conducted a proof-of-concept study to test a DNA-based approach to detect C. pomonella prey in the diets of birds occupying organic apple orchards. We tested published Tortricidae primers, polymerase chain reaction (PCR) and sequencing for detection of C. pomonella in avian feces. We also tested the quality of DNA isolated and purified from fecal samples using two DNA extraction kits. Finally, we field-tested this tool to identify the presence or absence of C. pomonella in the laboratory and from field samples. C. pomonella DNA was amplified in less than 1% of field samples and was successfully sequenced in 0.5%. A single species, the brown-headed cowbird Molothrus ater (Boddaert), had fecal samples positive for C. pomonella DNA. While our results do not provide evidence that birds play a strong role in the control of C. pomonella in western Colorado organic apple orchards, the approach we present is a new tool for understanding bird-mediated ecosystem services, avian feeding ecology, and supporting management decisions for sustainable agricultural practices and farmland biodiversity

Genomic analyses of gray fox lineages suggest ancient divergence and secondary contact in the southern Great Plains

The gray fox (Urocyon cinereoargenteus) lineage diverged from all other extant canids at their most basal node and is restricted to the Americas. Previous mitochondrial analysis from coastal populations identified deeply divergent (up to 1 Mya) eastern and western lineages that predate most intraspecific splits in carnivores. We conducted genotyping by sequencing and mitochondrial analysis on gray foxes sampled across North America to determine geographic concordance between nuclear and mitochondrial contact zones and divergence times. We also estimated the admixture within the contact zone between eastern and western gray foxes based on nuclear DNA. Both datasets confirmed that eastern and western lineages met in the southern Great Plains (i.e. Texas and Oklahoma), where they maintained high differentiation. Admixture was generally low, with the majority of admixed individuals carrying \u3c10% ancestry from the other lineage. Divergence times confirmed a mid-Pleistocene split, similar to the mitochondrial estimates. Taken together, findings suggest gray fox lineages represent an ancient divergence event, far older than most intraspecific divergences in North American carnivores. Low admixture may reflect a relatively recent time since secondary contact (e.g. post-Pleistocene) or, alternatively, ecological or reproductive barriers between lineages. Though further research is needed to disentangle these factors, our genomic investigation suggests species-level divergence exists between eastern and western gray fox lineages

Comparison of the collagen haemostat Sangustop(R) versus a carrier-bound fibrin sealant during liver resection; ESSCALIVER-study

Background: Haemostasis in liver surgery remains a challenge despite improved resection techniques. Oozing from blood vessels too small to be ligated necessitate a treatment with haemostats in order to prevent complications attributed to bleeding. There is good evidence from randomised trials for the efficacy of fibrin sealants, on their own or in combination with a carrier material. A new haemostatic device is Sangustop(R). It is a collagen based material without any coagulation factors. Pre-clinical data for Sangustop(R) showed superior haemostatic effect. This present study aims to show that in the clinical situation Sangustop(R) is not inferior to a carrier-bound fibrin sealant (Tachosil(R)) as a haemostatic treatment in hepatic resection. Methods: This is a multi-centre, patient-blinded, intra-operatively randomised controlled trial. A total of 126 patients planned for an elective liver resection will be enrolled in eight surgical centres. The primary objective of this study is to show the non-inferiority of Sangustop(R) versus a carrier-bound fibrin sealant (Tachosil(R)) in achieving haemostasis after hepatic resection. The surgical intervention is standardised with regard to devices and techniques used for resection and primary haemostasis. Patients will be followed-up for three months for complications and adverse events. Discussion: This randomised controlled trial (ESSCALIVER) aims to compare the new collagen haemostat Sangustop(R) with a carrier-bound fibrin sealant which can be seen as a "gold standard" in hepatic and other visceral organ surgery. If non-inferiority is shown other criteria than the haemostatic efficacy (e.g. costs, adverse events rate) may be considered for the choice of the most appropriate treatment. Trial Registration: NCT0091861

Position Sense Deficits at the Lower Limbs in Early Multiple Sclerosis: Clinical and Neural Correlates

Background/Objective. Position sense, defined as the ability to identify joint and limb position in space, is crucial for balance and gait but has received limited attention in patients with multiple sclerosis (MS). We investigated lower limb position sense deficits, their neural correlates, and their effects on standing balance in patients with early MS. Methods. A total of 24 patients with early relapsing-remitting MS and 24 healthy controls performed ipsilateral and contralateral matching tasks with the right foot during functional magnetic resonance imaging. Corpus callosum (CC) integrity was estimated with diffusion tensor imaging. Patients also underwent an assessment of balance during quiet standing. We investigated differences between the 2 groups and the relations among proprioceptive errors, balance performance, and functional/structural correlates. Results. During the contralateral matching task, patients demonstrated a higher matching error than controls, which correlated with the microstructural damage of the CC and with balance ability. In contrast, during the ipsilateral task, the 2 groups showed a similar matching performance, but patients displayed a functional reorganization involving the parietal areas. Neural activity in the frontoparietal regions correlated with the performance during both proprioceptive matching tasks and quiet standing. Conclusion. Patients with early MS had subtle, clinically undetectable, position sense deficits at the lower limbs that, nevertheless, affected standing balance. Functional changes allowed correct proprioception processing during the ipsilateral matching task but not during the more demanding bilateral task, possibly because of damage to the CC. These findings provide new insights into the mechanisms underlying disability in MS and could influence the design of neurorehabilitation protocols

Rooting Out Genetic Structure of Invasive Wild Pigs in Texas

Invasive wild pigs (Sus scrofa), also called feral swine or wild hogs, are recognized as among the most destructive invasive species in the world. Throughout the United States, invasive wild pigs have expanded rapidly over the past 40 years with populations now established in 38 states. Of the estimated 6.9 million wild pigs distributed throughout the United States, Texas supports approximately 40% of the population and similarly bears disproportionate ecological and economic costs. Genetic analyses are an effective tool for understanding invasion pathways and tracking dispersal of invasive species such as wild pigs and have been used recently in California and Florida, USA, which have similarly long-established populations and high densities of wild pigs. Our goals were to use molecular approaches to elucidate invasion and migration processes shaping wild pig populations throughout Texas, compare our results with patterns of genetic structure observed in California and Florida, and provide insights for effective management of this invasive species. We used a high-density single nucleotide polymorphism (SNP) array to evaluate population genetic structure. Genetic clusters of wild pigs throughout Texas demonstrate 2 distinct patterns: weakly resolved, spatially dispersed clusters and well-resolved, spatially localized clusters. The disparity in patterns of genetic structure suggests disparate processes are differentially shaping wild pig populations in various localities throughout the state. Our results differed from the patterns of genetic structure observed in California and Florida, which were characterized by localized genetic clusters. These differences suggest distinct biological and perhaps anthropogenic processes are shaping genetic structure in Texas. Further, these disparities demonstrate the need for location-specific management strategies for controlling wild pig populations and mitigating associated ecological and economic costs

Vigilancia epidemiológica en mujeres embarazadas para control de riesgos en el consumo de tabaco en la ciudad de Gualeguaychú

Objetivo: Determinar el nivel de cotinina urinaria en embarazadas fumadoras activas y pasivas en centros de salud públicos (cpub) y privados (cpri) de Gualeguaychú para conocer su riesgo de exposición y contribuir a mejorar el diseño de las intervenciones en la prevención del hábito tabáquico durante el embarazo. Materiales y métodos: Se trabajó con 443 embarazadas que concurrieron a cpub y cpri de Gualeguaychú para su control prenatal, solicitándoles a las que manifestaron ser fumadoras activas o estar expuestas al hat una muestra de orina para el dosaje de cotinina. Se aplicó un diseño de tipo no experimental, retrospectivo y de corte transversal. El dosaje de cotinina se realizó en orina, empleando una metodología quimioluminiscente. Previamente se obtuvo un valor referencial de cotinina urinaria inferior a los 15,2 ng/ml para el 98 % de sujetos no fumadores no expuestos al hat. Resultados: El 97,3 % de las embarazadas que declararon ser fumadoras activas presentaron valores de cotinina superiores a los 100 ng/ml y el 66,2 % de las que expresaron ser fumadoras pasivas presentaron un nivel superior a 15,2 ng/ml. Discusión y conclusiones: Los resultados obtenidos demuestran la utilidad de la cotinina como indicador para obtener datos fidedignos frente a la exposición al tabaco