Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
589
result(s) for
"Smith, Mathew"
Sort by:
What do we gain from simplicity versus complexity in species distribution models?
by
Zimmermann, Niklaus E.
,
Merow, Cory
,
Thuiller, Wilfried
in
attitudes and opinions
,
biogeography
,
guidelines
2014
Species distribution models (SDMs) are widely used to explain and predict species ranges and environmental niches. They are most commonly constructed by inferring species' occurrence–environment relationships using statistical and machine-learning methods. The variety of methods that can be used to construct SDMs (e.g. generalized linear/additive models, tree-based models, maximum entropy, etc.), and the variety of ways that such models can be implemented, permits substantial flexibility in SDM complexity. Building models with an appropriate amount of complexity for the study objectives is critical for robust inference. We characterize complexity as the shape of the inferred occurrence–environment relationships and the number of parameters used to describe them, and search for insights into whether additional complexity is informative or superfluous. By building ‘under fit’ models, having insufficient flexibility to describe observed occurrence–environment relationships, we risk misunderstanding the factors shaping species distributions. By building ‘over fit’ models, with excessive flexibility, we risk inadvertently ascribing pattern to noise or building opaque models. However, model selection can be challenging, especially when comparing models constructed under different modeling approaches. Here we argue for a more pragmatic approach: researchers should constrain the complexity of their models based on study objective, attributes of the data, and an understanding of how these interact with the underlying biological processes. We discuss guidelines for balancing under fitting with over fitting and consequently how complexity affects decisions made during model building. Although some generalities are possible, our discussion reflects differences in opinions that favor simpler versus more complex models. We conclude that combining insights from both simple and complex SDM building approaches best advances our knowledge of current and future species ranges.
Journal Article
Genetic Diversity and Host Specificity Varies across Three Genera of Blood Parasites in Ducks of the Pacific Americas Flyway
2015
Birds of the order Anseriformes, commonly referred to as waterfowl, are frequently infected by Haemosporidia of the genera Haemoproteus, Plasmodium, and Leucocytozoon via dipteran vectors. We analyzed nucleotide sequences of the Cytochrome b (Cytb) gene from parasites of these genera detected in six species of ducks from Alaska and California, USA to characterize the genetic diversity of Haemosporidia infecting waterfowl at two ends of the Pacific Americas Flyway. In addition, parasite Cytb sequences were compared to those available on a public database to investigate specificity of genetic lineages to hosts of the order Anseriformes. Haplotype and nucleotide diversity of Haemoproteus Cytb sequences was lower than was detected for Plasmodium and Leucocytozoon parasites. Although waterfowl are presumed to be infected by only a single species of Leucocytozoon, L. simondi, diversity indices were highest for haplotypes from this genus and sequences formed five distinct clades separated by genetic distances of 4.9%-7.6%, suggesting potential cryptic speciation. All Haemoproteus and Leucocytozoon haplotypes derived from waterfowl samples formed monophyletic clades in phylogenetic analyses and were unique to the order Anseriformes with few exceptions. In contrast, waterfowl-origin Plasmodium haplotypes were identical or closely related to lineages found in other avian orders. Our results suggest a more generalist strategy for Plasmodium parasites infecting North American waterfowl as compared to those of the genera Haemoproteus and Leucocytozoon.
Journal Article
Integrative interactomics applied to bovine fescue toxicosis
2022
Bovine fescue toxicosis (FT) is caused by grazing ergot alkaloid-producing endophyte (
Epichloë coenophiala
)-infected tall fescue. Endophyte’s effects on the animal’s microbiota and metabolism were investigated recently, but its effects
in planta
or on the plant–animal interactions have not been considered. We examined multi-compartment microbiota–metabolome perturbations using multi-‘omics (16S and ITS2 sequencing, plus untargeted metabolomics) in Angus steers grazing non-toxic (Max-Q) or toxic (E+) tall fescue for 28 days and in E+ plants. E+ altered the plant/animal microbiota, decreasing most ruminal fungi, with mixed effects on rumen bacteria and fecal microbiota. Metabolic perturbations occurred in all matrices, with some plant-animal overlap (e.g., Vitamin B6 metabolism). Integrative interactomics revealed unique E+ network constituents. Only E+ had ruminal solids OTUs within the network and fecal fungal OTUs in E+ had unique taxa (e.g.,
Anaeromyces
). Three E+-unique urinary metabolites that could be potential biomarkers of FT and targeted therapeutically were identified.
Journal Article
Effect of Cochlear Implantation on Air Conduction and Bone Conduction Elicited Vestibular Evoked Myogenic Potentials—A Scoping Review
by
Bance, Manohar L.
,
Borsetto, Daniele
,
Ayas, Muhammed
in
Analysis
,
Audiometry
,
Cochlear implants
2024
Background/Objectives: Cochlear implantation (CI) is an effective intervention for individuals with severe to profound hearing loss; however, it may impact vestibular function due to its proximity to related anatomical structures. Vestibular evoked myogenic potentials (VEMPs) assess the function of the saccule and utricle, critical components of the vestibular system. This review examines CI’s impact on air conduction (AC) and bone conduction (BC) VEMP responses. Methods: A scoping review was conducted following PRISMA guidelines, using databases such as Medline, Embase, Cochrane Library, Scopus, and ProQuest Dissertations. Studies reporting on AC and/or BC-VEMP in CI recipients were included. Data extraction focused on VEMP response rates, amplitudes, and latencies pre- and post-CI. Risk of bias/quality assessment was performed using the Newcastle–Ottawa Scale. Results: Out of 961 studies identified, 4 met the inclusion criteria, encompassing a total of 245 CI-implanted ears. Results indicated that AC-VEMP responses were often reduced or absent post-CI, reflecting the influence of surgical changes in the middle ear mechanics rather than otolith dysfunction. In contrast, BC-VEMP responses were more consistently preserved, suggesting that BC stimuli bypass the middle ear and more accurately delineate otolith function. Variations in VEMP outcomes were noted depending on the surgical approach and individual patient factors. Conclusions: CI impacts vestibular function as measured by VEMP, with AC-VEMP showing greater susceptibility to postoperative changes compared to BC-VEMP. The presence of preserved BC-VEMP alongside absent AC-VEMP underscores the need to differentiate between these measures in assessing vestibular function.
Journal Article
Symptomatic Pneumorrhachis from Bronchial-Subarachnoid Fistula
by
Lipinski, Alexander W.
,
Smith, Mathew V.
,
Timpone, Vincent M.
in
Back surgery
,
bronchial-subarachnoid fistula
,
Care and treatment
2024
Bronchial-subarachnoid fistulas are rare occurrences, which are not well defined in the literature. This uncommon clinical phenomenon may result in symptomatic pneumorrhachis and presents unique clinical challenges. This report details a case of a 53-year-old female whose treatment for recurrent chondrosarcoma of the thoracic spine included multiple surgeries and radiotherapy. Two weeks after her most recent debulking surgery, she experienced a rapid onset of unusual symptoms, including headache, back and neck spasms, bladder incontinence, and confusion. The source of her symptoms was found to be secondary to pneumorrhachis from a pre-existing bronchial-pleural fistula that had fistulized to the subarachnoid space discovered on computed tomography (CT) and confirmed intraoperatively. The patient was treated successfully with high-flow oxygen therapy and bed rest, followed by surgical correction of both a pleural air leak and a dural defect with muscular flaps. The patient was discharged home in stable condition and remained clinically free of recurrent bronchial-subarachnoid fistula six months after surgical repair. This case contributes to the existing literature by providing detailed clinical insights into the diagnosis and successful management of a bronchial-subarachnoid fistula leading to pneumorrhachis, thereby highlighting the importance of early recognition and intervention and underscoring the need for further research in this area.
Journal Article
Results from the Supernova Photometric Classification Challenge
by
González-Gaitán, Santiago
,
Conley, Alex
,
Lampeitl, Hubert
in
Astronomy
,
Earth, ocean, space
,
Exact sciences and technology
2010
We report results from the Supernova Photometric Classification Challenge (SNPhotCC), a publicly released mix of simulated supernovae (SNe), with types (Ia, Ibc, and II) selected in proportion to their expected rates. The simulation was realized in the
griz
g
r
i
z
filters of the Dark Energy Survey (DES) with realistic observing conditions (sky noise, point-spread function, and atmospheric transparency) based on years of recorded conditions at the DES site. Simulations of non–Ia-type SNe are based on spectroscopically confirmed light curves that includeunpublishednon-Ia samples donated from the Carnegie Supernova Project (CSP), the Supernova Legacy Survey (SNLS), and the Sloan Digital Sky Survey-II (SDSS-II). A spectroscopically confirmed subset was provided for training. We challenged scientists to run their classification algorithms and report a type and photo-
z
z
for each SN. Participants from 10 groups contributed 13 entries for the sample that included a host-galaxy photo-
z
z
for each SN and nine entries for the sample that had no redshift information. Several different classification strategies resulted in similar performance, and for all entries the performance was significantly better for the training subset than for the unconfirmed sample. For the spectroscopically unconfirmed subset, the entry with the highest average figure of merit for classifying SNe Ia has an efficiency of 0.96 and an SN Ia purity of 0.79. As a public resource for the future development of photometric SN classification and photo-
z
z
estimators, we have released updated simulations with improvements based on our experience from the SNPhotCC, added samples corresponding to the Large Synoptic Survey Telescope (LSST) and the SDSS-II, and provided the answer keys so that developers can evaluate their own analysis.
Journal Article
Effects of pathogenic CNVs on physical traits in participants of the UK Biobank
by
Kendall, Kimberley M.
,
O’Donovan, Michael C.
,
Escott-Price, Valentina
in
Adults
,
Analysis
,
Animal Genetics and Genomics
2018
Background
Copy number variants (CNVs) have been shown to increase risk for physical anomalies, developmental, psychiatric and medical disorders. Some of them have been associated with changes in weight, height, and other physical traits. As most studies have been performed on children and young people, these effects of CNVs in middle-aged and older people are not well established. The UK Biobank recruited half a million adults who provided a variety of physical measurements. We called all CNVs from the Affymetrix microarrays and selected a set of 54 CNVs implicated as pathogenic (including their reciprocal deletions/duplications) and that were found in five or more persons. Linear regression analysis was used to establish their association with 16 physical traits relevant to human health.
Results
396,725 participants of white British or Irish descent (excluding first-degree relatives) passed our quality control filters. Out of the 864 CNV/trait associations, 214 were significant at a false discovery rate of 0.1, most of them novel. Many of these traits increase risk for adverse health outcomes: e.g. increases in weight, waist-to-hip ratio, pulse rate and body fat composition. Deletions at 16p11.2, 16p12.1,
NRXN1
and duplications at 16p13.11 and 22q11.2 produced the highest numbers of significant associations. Five CNVs produced average changes of over one standard deviation for the 16 traits, compared to controls: deletions at 16p11.2 and 22q11.2, and duplications at 3q29, the Williams-Beuren and Potocki-Lupski regions. CNVs at 1q21.1, 2q13, 16p11.2 and 16p11.2 distal, 16p12.1, 17p12 and 17q12 demonstrated one or more mirror image effects of deletions versus duplications.
Conclusions
Carriers of many CNVs should be monitored for physical traits that increase morbidity and mortality. Genes within these CNVs can give insights into biological processes and therapeutic interventions.
Journal Article
Caveolin-1 in renal cell carcinoma promotes tumour cell invasion, and in co-operation with pERK predicts metastases in patients with clinically confined disease
by
Griffiths, Rosie
,
Gutteridge, Robert
,
Gumbleton, Nigel
in
Biology
,
Biomarkers
,
Biomedical and Life Sciences
2013
Background
Up to 40% of patients initially diagnosed with clinically-confined renal cell carcinoma (RCC) and who undergo curative surgery will nevertheless relapse with metastatic disease (mRCC) associated with poor long term survival. The discovery of novel prognostic/predictive biomarkers and drug targets is needed and in this context the aim of the current study was to investigate a putative caveolin-1/ERK signalling axis in clinically confined RCC, and to examine in a panel of RCC cell lines the effects of caveolin-1 (Cav-1) on pathological processes (invasion and growth) and select signalling pathways.
Methods
Using immunohistochemistry we assessed the expression of both Cav-1 and phosphorylated-ERK (pERK) in 176 patients with clinically confined RCC, their correlation with histological parameters and their impact upon disease-free survival. Using a panel of RCC cell lines we explored the functional effects of Cav-1 knockdown upon cell growth, cell invasion and VEGF-A secretion, as well Cav-1 regulation by cognate cell signalling pathways.
Results
We found a significant correlation (
P
= 0.03) between Cav-1 and pERK in a cohort of patients with clinically confined disease which represented a prognostic biomarker combination (HR = 4.2) that effectively stratified patients into low, intermediate and high risk groups with respect to relapse, even if the patients’ tumours displayed low grade and/or low stage disease. In RCC cell lines Cav-1 knockdown unequivocally reduced cell invasive capacity while also displaying both pro-and anti-proliferative effects; targeted knockdown of Cav-1 also partially suppressed VEGF-A secretion in VHL-negative RCC cells. The actions of Cav-1 in the RCC cell lines appeared independent of both ERK and AKT/mTOR signalling pathways.
Conclusion
The combined expression of Cav-1 and pERK serves as an independent biomarker signature with potential merit in RCC surveillance strategies able to predict those patients with clinically confined disease who will eventually relapse. In a panel of in-vitro RCC cells Cav-1 promotes cell invasion with variable effects on cell growth and VEGF-A secretion. Cav-1 has potential as a therapeutic target for the prevention and treatment of mRCC.
Journal Article
Patient satisfaction with primary care physician performance in a multicultural population
2020
Background
A key component of the quality of health care is patient satisfaction, particularly in regard to Primary Care Physician (PCP), which represents the first contact with health care services. Patient satisfaction is associated with ethnic, regional and socio-demographic differences, due to differences in service quality, patient-doctor communication, and the patient’s perceptions. The aim of this study was to evaluate patients’ satisfaction related to primary care physicians’ (PCP) performance and to explore potential differences by ethnicity in a multicultural population.
Methods
A national cross-sectional telephone survey was conducted, among a random sample of the Israeli population aged ≥25 years. Satisfaction level from performance of PCP was assessed using a validated questionnaire (30 items; 6 different domains).
Results
The final sample included (
n
= 827 Jews;
n
= 605 Arabs, mean age 54.7(±14.9). In the adjusted logistic regression models, Arabs reported lower general satisfaction related to PCPs’ performance as compared to Jews (adjusted odds ratio (AOR), 0.63; (95% CI: 0.40–0.98). Arabs reported lower satisfaction related to PCPs’ performance across the following domains: communication skills (AOR, 0.42; 95% CI, 0.22–0.82); interpersonal manners (AOR, 0.37; 95% CI, 0.24–0.58); and time spent with the patients (AOR, 0.60; 95% CI, 0.43–0.85).
Conclusions
Jews and Arabs were very satisfied with PCPs’ performance. However, there are ethnic differences in the extent of satisfaction level related to the performance of PCP. Satisfaction from PCPs’ performance may be achieved by improving the communication skills of the PCP, encouraging interpersonal interaction between the PCP and the patient, and devoting more time to the patient during the visits.
Journal Article
Coping and Sexual Harassment: How Victims Cope across Multiple Settings
by
Smith, Mathew
,
Sheff, Sarah E.
,
Scarduzio, Jennifer A.
in
Alienation
,
Behavioral Science and Psychology
,
Blame
2018
The ways sexual harassment occurs both online and in face-to-face settings has become more complicated. Sexual harassment that occurs in cyberspace or online sexual harassment adds complexity to the experiences of victims, current research understandings, and the legal dimensions of this phenomenon. Social networking sites (SNS) are a type of social media that offer unique opportunities to users and sometimes the communication that occurs on SNS can cross the line from flirtation into online sexual harassment. Victims of sexual harassment employ communicative strategies such as coping to make sense of their experiences of sexual harassment. The current study qualitatively examined problem-focused, active emotion-focused, and passive emotion-focused coping strategies employed by sexual harassment victims across multiple settings. We conducted 26 in-depth interviews with victims that had experienced sexual harassment across multiple settings (e.g., face-to-face and SNS). The findings present 16 types of coping strategies—five problem-focused, five active emotion-focused, and six passive emotion-focused. The victims used an average of three types of coping strategies during their experiences. Theoretical implications extend research on passive emotion-focused coping strategies by discussing powerlessness and how victims blame other victims. Furthermore, theoretically the findings reveal that coping is a complex, cyclical process and that victims shift among types of coping strategies over the course of their experience. Practical implications are offered for victims and for SNS sites.
Journal Article