Publications by authors named "Harmsen B"

Training personnel to work with animals presents a variety of challenges, both logistically and with regard to animal welfare. These issues make training an ideal opportunity to evaluate practices and to implement the 3R principles (refinement, replacement, and reduction). Cardiac blood collection from mice is a procedure that can compromise the 3Rs by requiring repeated practice and animal euthanasia.

View Article and Find Full Text PDF

The submental route is an option for nonterminal and serial blood collection in mice. This study compared the submental route to the maxillary route (also referred to as the submandibular route). The study used male CD1 and C57BL/6 strains of mice in 2 age groups: 8 and 19 wk.

View Article and Find Full Text PDF

Prey remains found in carnivore scats provide generalised dietary profiles of sampled populations. The profile may be biased if individual diets differ and some individuals are over- or under-represented in the sample. Quantifying individual contributions allows us to recognise these potential biases and better interpret generalised profiles.

View Article and Find Full Text PDF

Population assessments of wide-ranging, cryptic, terrestrial mammals rely on camera trap surveys. While camera trapping is a powerful method of detecting presence, it is difficult distinguishing rarity from low detection rate. The margay (Leopardus wiedii) is an example of a species considered rare based on its low detection rates across its range.

View Article and Find Full Text PDF

We estimated jaguar density and tenure, and investigated ranging behavior, using camera traps across the Maya Forest Corridor, a human-influenced landscape in central Belize that forms the only remaining connection for jaguar populations inhabiting two regional forest blocks: the Selva Maya and the Maya Mountain Massif. Jaguars were ubiquitous across the study area. Similar to the neighboring Selva Maya, mean density ranged from 1.

View Article and Find Full Text PDF

Quantifying the distribution of daily activity is an important component of behavioral ecology. Historically, it has been difficult to obtain data on activity patterns, especially for elusive species. However, the development of affordable camera traps and their widespread usage has led to an explosion of available data from which activity patterns can be estimated.

View Article and Find Full Text PDF

Modern and paleoclimate changes may have altered species dynamics by shifting species' niche suitability over space and time. We analyze whether the current genetic structure and isolation of the two large American felids, jaguar (Panthera onca) and puma (Puma concolor), are mediated by changes in climatic suitability and connection routes over modern and paleoclimatic landscapes. We estimate species distribution under 5 climatic landscapes (modern, Holocene, last maximum glaciations [LMG], average suitability, and climatic instability) and correlate them with individuals' genetic isolation through causal modeling on a resemblance matrix.

View Article and Find Full Text PDF

Camera trapping is the standard field method of monitoring cryptic, low-density mammal populations. Typically, researchers run camera surveys for 60 to 90 days and estimate density using closed population spatially explicit capture-recapture (SCR) models. The SCR models estimate density, capture probability (g0), and a scale parameter (σ) that reflects ranging behaviour.

View Article and Find Full Text PDF

Background: Connectivity among jaguar (Panthera onca) populations will ensure natural gene flow and the long-term survival of the species throughout its range. Jaguar conservation efforts have focused primarily on connecting suitable habitat in a broad-scale. Accelerated habitat reduction, human-wildlife conflict, limited funding, and the complexity of jaguar behaviour have proven challenging to maintain connectivity between populations effectively.

View Article and Find Full Text PDF

Human activity affecting the welfare of wild vertebrates, widely accepted to be sentient, and therefore deserving of moral concern, is widespread. A variety of motives lead to the killing of individual wild animals. These include to provide food, to protect stock and other human interests, and also for sport.

View Article and Find Full Text PDF

Open population capture-recapture models are widely used to estimate population demographics and abundance over time. Bayesian methods exist to incorporate open population modeling with spatial capture-recapture (SCR), allowing for estimation of the effective area sampled and population density. Here, open population SCR is formulated as a hidden Markov model (HMM), allowing inference by maximum likelihood for both Cormack-Jolly-Seber and Jolly-Seber models, with and without activity center movement.

View Article and Find Full Text PDF
Article Synopsis
  • The study examines how local mammalian carnivore communities impact terrestrial ecosystems by analyzing camera trap data from 12 countries across five continents, covering 108,087 trap days.
  • Researchers found that certain species of carnivores tend to co-occur more often than expected, especially when they share ecological traits like body size, activity patterns, and diet.
  • The presence of large carnivores influences these dynamics negatively, indicating that both shared traits and the presence of top predators regulate carnivore community structures globally.
View Article and Find Full Text PDF

Background: Details of how, why and in what conditions large felids make scrapes is unknown. Here, we examined the general hypothesis about the use of scrapes for marking proposals, as well as to communicate with other individuals to signalize particular points or areas of interest, by studying scrape-marking behaviour of jaguars and pumas.

Methods: We surveyed by scrapes between five days and two months mainly during dry season in five study areas from Mexico (El Edén and San Ignacio), Belize (Cockscomb) and Brazil (Angatuba and Serra das Almas), which differed in presence and/or abundance of jaguars and pumas.

View Article and Find Full Text PDF

Objective: To determine if autonomic dysfunction, cognitive disorders or axial disability are associated with white matter lesions (WML) in Parkinson disease (PD).

Methods: We performed a retrospective cross-sectional review study on 204 consecutive PD patients who underwent cerebral MRI in our center between January 2012 and July 2016. For each patient, we scored the severity of WML and PV (periventricular) WML using the Fazekas score and using the ARWMC scale for WML and BG (basal ganglia) and clinical characteristics such as neurogenic orthostatic hypotension and cognitive function.

View Article and Find Full Text PDF
Article Synopsis
  • The study analyzes a protected jaguar population in Belize using 14 years of camera-trap data (2002-2015), examining individual survival and behavior across 3,075 detection events of 105 adult jaguars.
  • High and consistent survival rates (φ = 0.78) were observed for both sexes, while temporary emigration was stable at 0.20 per year, indicating a stable population of resident males with fluctuating transient males and low detection rates for females.
  • The findings suggest the need for extended survey periods to improve female detection and emphasize the importance of long-term monitoring to better understand the dynamics of elusive predator populations.
View Article and Find Full Text PDF

Different solid state forms of the research chemical fasoracetam, which counters the effects of Alzheimer's disease, have been subjected to a thermal and structural analysis. Single crystals were obtained from solution evaporation and from the melt. Single-crystal X-ray analyses of the crystals show the existence of 2 hydrated and 1 non-hydrated crystalline form of fasoracetam.

View Article and Find Full Text PDF
Article Synopsis
  • The study reports new findings of tick species collected from wild mammals in Belize, providing new data on tick biodiversity in Central America.
  • It identifies three rickettsial agents, including one previously unreported in Central America, expanding knowledge on the presence and distribution of rickettsial infections in the region.
  • The research underscores the importance of monitoring tick-borne infections, indicating a broader range of rickettsial pathogens in Latin America than previously known.
View Article and Find Full Text PDF

The solution structure of the 18-kDa single-stranded DNA binding protein encoded by the filamentous Pseudomonas bacteriophage Pf3 has been refined using 40 ms 15N- and 13C-edited NOESY spectra and many homo- and heteronuclear J-couplings. The structures are highly precise, but some variation was found in the orientation of the beta-hairpin denoted the DNA binding wing with respect to the core of the protein. Backbone dynamics of the protein was investigated in the presence and absence of DNA by measuring the R1 and R2 relaxation rates of the 15N nuclei and the 15N-1H NOE.

View Article and Find Full Text PDF

The DNA binding domain of the single-stranded DNA binding protein gene V protein encoded by the bacteriophage M13 was studied by means of 1H nuclear magnetic resonance, through use of a spin-labeled deoxytrinucleotide. The paramagnetic relaxation effects observed in the 1H-NMR spectrum of M13 GVP upon binding of the spin-labeled ligand were made manifest by means of 2D difference spectroscopy. In this way, a vast data reduction was accomplished which enabled us to check and extend the analysis of the 2D spectra carried out previously as well as to probe the DNA binding domain and its surroundings.

View Article and Find Full Text PDF

Scrutiny of NOE data available for the protein encoded by gene V of the filamentous phage IKe (IKe GVP), resulted in the elucidation of a beta-sheet structure which is partly five stranded. The DNA-binding domain of IKe GVP was investigated using a spin-labeled deoxytrinucleotide. The paramagnetic-relaxation effects observed in the 1H-NMR spectrum of IKe GVP, upon binding of this DNA fragment, could be visualized using two-dimensional difference spectroscopy.

View Article and Find Full Text PDF

This investigation describes how the binding characteristics of the single-stranded DNA-binding protein encoded by gene V of bacteriophage M13, are affected by single-site amino acid substitutions. The series of mutant proteins tested includes mutations in the purported monomer-monomer interaction region as well as mutations in the DNA-binding domain at positions which are thought to be functionally involved in monomer-monomer interaction or single-stranded DNA binding. The characteristics of the binding of the mutant proteins to the homopolynucleotides poly(dA), poly(dU) and poly(dT), were studied by means of fluorescence-titration experiments.

View Article and Find Full Text PDF

By means of 2D NMR techniques, all backbone resonances in the 1H NMR spectrum of the single-stranded DNA binding protein encoded by gene V of the filamentous phage IKe have been assigned sequence specifically (at pH 4.6, T = 298 K). In addition, a major part of the side chain resonances could be assigned as well.

View Article and Find Full Text PDF