Logging Impacts in Tropical Lowland Humid Forest on Tree Species Diversity and Environmental Conservation

This study assessed the effects of exploitations in natural forest ecosystems on tree species diversity and environmental conservation. This was achieved by comparing tree species diversity and yield in an unlogged forest (Strict Nature Reserve) and a forest reserve where active logging is in progress in Ondo State, Nigeria. Eight plots (20 m × 20 m) were assessed in each site using systematic sampling techniques. All living trees with dbh >10 cm were identified, categorized into families with their diameter at breast height (dbh) measured in each plot. Shannon-Weiner and species evenness indices were used to assess and compare tree species diversity and abundance. The results show that the tropical humid forest is very rich in tree species, as a total of 54 different tropical hardwood species from 23 families were encountered in both forest types. There were 46 species distributed among 21 families in the unlogged forest and 24 species in 14 families in the logged forest. Shannon-Weiner diversity index of 3.16 and 3.03 and evenness index of .83 and .81 were also obtained for the unlogged and logged forest, respectively. Every variable computed had a higher value in the unlogged forest relative to the logged forest. In the unlogged forest, the species with the highest number of occurrence was Mansonia altissima A. Chev. (80 stems/ha). Caesalpinoidae and Sterculiaceae families had the highest number of species (6). In the logged forest, Triplochiton scleroxylon K. Schum. (18 stems/ha) had the highest frequency and Caesalpinoidae family has the highest number of species (4). The study concludes that exploitation has affected species diversity in the ecosystem and subsequently, the roles of trees in environmental conservation are affected.     

Grafts of porcine small intestinal submucosa seeded with cultured homologous smooth muscle cells for bladder repair in dogs

Background

Due to numerous complications associated to gastrointestinal augmented cystoplasty, this study aimed to analyze the anatomic repair of the bladder of 10 female dogs using grafts of porcine small intestinal submucosa (SIS) seeded with cultured homologous smooth muscle cells, and compare them with the acellular SIS grafts.

Results

We assessed the possible side effects and complications of each type of graft by clinical examination, abdominal ultrasound and laboratory findings. Anatomic repair of neoformed bladder was assessed by histological staining for H/E and Masson''s Trichrome, analyzed with a Nikon Photomicroscope connected to the system of image analysis Image J.

Conclusions

We propose that SIS associated to homologous smooth cells can improve the quality of tissue repair, and consequently decrease the potential complications inherent to acellular SIS.     

Evaluation of Methods to Determine Sperm Density for the European eel,Anguilla anguilla

European eel, Anguilla anguilla, is a target species for future captive breeding, yet best methodology to estimate sperm density for application in in vitro fertilization is not established. Thus, our objectives were to evaluate methods to estimate European eel sperm density including spermatocrit, computer‐assisted sperm analysis (CASA) and flow cytometry (FCM), using Neubauer Improved haemocytometer as benchmark. Initially, relationships between spermatocrit, haemocytometer counts and sperm motility were analysed, as well as the effect of sperm dilution on haemocytometer counts. Furthermore, accuracy and precision of spermatocrit, applying a range of G‐forces, were tested and the best G‐force used in method comparisons. We found no effect of dilution on haemocytometer sperm density estimates, whereas motility associated positively with haemocytometer counts, but not with spermatocrit. Results from all techniques, spermatocrit, CASA and FCM, showed significant positive correlations with haemocytometer counts. The best correlation between spermatocrit and haemocytometer counts was obtained at 6000 ×  g (r = 0.68). Of two CASA variants, one or three photographic fields (CASA‐1 and CASA‐2), CASA‐2 showed a very high accuracy to haemocytometer counts (r  =  0.93), but low precision (CV: CASA‐2 = 28.4%). FCM was tested with and without microfluorospheres (FCM‐1 and FCM‐2), and relationships to haemocytometer counts were highly accurate (FCM‐1: r  =  0.94; FCM‐2: r  =  0.88) and precise (CV: FCM‐1 = 2.5; FCM‐2 = 2.7%). Overall, CASA‐2 and FCM‐1 feature reliable methods for quantification of European eel sperm, but FCM‐1 has a clear advantage featuring highest precision and accuracy. Together, these results provide a useful basis for gamete management in fertilization protocols.     

Genetic variability in Colombian Creole cattle populations estimated by pedigree information

The genetic structure of 4 Colombian Creole cattle breeds, namely, Coste?o con Cuernos, Blanco Orejinegro (BON), Romosinuano (ROMO), and Sanmartinero (SM), was studied with an analysis of the available pedigree data. The comparison between the effective number of founders (f(e)) and the effective number of ancestors (f(a)) revealed a decrease in the genetic variation that was rather important for the ROMO and San Martinero breeds, which had the lowest f(a)/f(e) ratios (0.34 and 0.53, respectively). All breeds showed similar values for the number of equivalent generations traced, ranging from 3.1 in BON to 4.8 in ROMO. These 2 populations also had the lowest and the highest population sizes, respectively. The lowest average inbreeding coefficient considering the whole pedigree was obtained by BON (0.18%), whereas the highest was attained by ROMO (1.22%). Finally, the percentage of individuals with an inbreeding level greater than 6.25% in the reference population was high, indicating that the existing conservation management strategies could be improved to successfully maintain the genetic variability of these populations.     

Characterization of porcine circovirus type 2 (PCV2) infection in swine lymphocytes using mitogen-stimulated peripheral blood lymphocytes from healthy PCV2-carrier pigs

Information regarding the susceptibility of swine lymphocytes to PCV2 is rather limited. To further explore and characterize the PCV2 infection in swine lymphocytes, an in vitro model using concanavalin A (Con A)-stimulated peripheral blood lymphocytes (PBLs) obtained from clinically healthy PCV2-carrier pigs was introduced. It was found that the PCV2 antigen-containing rate was below 2% in PBLs from healthy PCV2-free pigs following treated simultaneously with Con A and PCV2. However, significantly higher PCV2 antigen- and nucleic acid-containing rates could be seen in Con A-stimulated PBLs from clinically healthy PCV2-carrier pigs. Prior to Con A treatment, both of the PCV2 antigen- and nucleic acid-containing rates in PBLs from healthy PCV2-carrier pigs were less than 1%; however, they reached 22.1+/-5.7% by flow cytometry and 27.1+/-6.5% by in situ hybridization, respectively, at 4-day post-incubation with Con A. Phenotyping of PCV2 antigen-containing cells revealed that PCV2-positive cells could be detected in both T and B lymphocyte populations within which IgM-positive B lymphocytes appeared to have a relatively higher positive rate. The Con A-stimulated PBLs also displayed a significantly higher viral load by the measurement of either PCV2 DNA copy number or viral titer when compared with the non-treated PBLs from healthy PCV2-carrier pigs. The results indicate that PBLs, especially IgM-bearing B lymphocytes, are indeed susceptible to PCV2 infection and PCV2 is capable of replicating in dividing lymphocytes. This activation-induced replication may explain in part the pathogenesis of lymphoid depletion in PMWS-affected pigs.     

Cervical thymoma originating in ectopic thymic tissue in a cat

Abstract: An 11‐year‐old female spayed domestic shorthair cat was referred to The Ohio State University Veterinary Teaching Hospital (OSU‐VTH) for evaluation of a 6 × 4 × 3.5 cm mass in the left midcervical region causing increased respiratory sounds and lateral deviation of the trachea. A fine needle aspirate of the mass was obtained before referral and the cytology results were compatible with a reactive lymph node. Immunocytochemistry showed increased numbers of CD3+ T lymphocytes and small numbers of CD20+ and CD79a+ medium to large lymphocytes. Differential diagnoses from the referral pathologist were T‐cell‐rich B‐cell lymphoma and feline Hodgkin's‐like lymphoma. A subsequent fine needle aspirate performed at the OSU‐VTH showed similar results. On flow cytometry the majority of cells were CD3+ T lymphocytes that were double positive for CD4 and CD8 (73%), compatible with either a double‐positive (CD4+CD8+) T‐cell lymphoma or lymphocytes from ectopic thymic tissue. The mass was surgically removed. Histopathology and immunohistochemistry of the mass revealed a predominant population of CD3+ small lymphocytes and small numbers of medium to large lymphocytes with moderate anisocytosis and anysokaryosis. A population of cytokeratin‐positive epithelial cells surrounded small microcystic structures filled with eosinophilic material and structures interpreted as Hassall's corpuscles. These findings were consistent with thymic tissue and a diagnosis of ectopic thymoma was made. PCR results for lymphocyte antigen receptor rearrangement (PARR) were negative. The cat had no evidence of disease 16 months after removal of the mass. To our knowledge this is the first report of an ectopic cervical thymoma in a cat. The clinical and diagnostic features of this unusual case will be useful in helping veterinarians and pathologists obtain a presurgical diagnosis and establish a prognosis for similar lesions.     

Genetic structure of the Amur tiger (Panthera tigris altaica) population: Are tigers in Sikhote‐Alin and southwest Primorye truly isolated?

We used molecular genetic analyses to noninvasively identify individual Amur tigers and define subpopulations of tigers in the Russian Far East. We identified 63 individuals after genotyping 256 feces, 7 hair and 11 blood samples collected within southern, central and northern Sikhote‐Alin, as well as Southwest Primorye. Analysis of nuclear DNA at 9 microsatellite loci demonstrated greater genetic similarity between animals from southern and northern Sikhote‐Alin (some 500 km apart) than between animals from Ussuriskii State Nature Reserve and Southwest Primorye (less than 10 km apart at their nearest point), suggesting that a true barrier exists preventing movements of tigers between Southwest Primorye and the southern Sikhote‐Alin Mountains.     

A model of the spring migration into the North Sea by Calanus finmarchicus overwintering off the Scottish continental shelf

A particle tracking model was used to investigate the annual spring invasion of the North Sea by Calanus finmarchicus copepodites which overwinter in deep water off the Scottish continental shelf. Flow fields generated by a hydrodynamic model (HDM) were used to simulate the advection of zero drag particles representing the copepods. Particles were released simultaneously from a regular lattice of start positions at a given depth ( D ₁), and ascended at a fixed rate ( dD/dt ) until they reached a final depth ( D ₂) in the surface layers. The proportion of particles reaching target areas in the northern North Sea was relatively insensitive to a moderate degree of variation (±20%) around chosen default values of the vertical migration parameters ( D ₁, D ₂ and dD/dt ), derived from field data. The inclusion of horizontal diffusion velocities and diel vertical migration in surface layers did not significantly affect the results. Sensitivity to wind direction was investigated by applying flow fields from HDM runs with different wind forcing scenarios. For the default vertical migration parameters, only north-westerly winds resulted in particles entering the North Sea from release locations north of the Iceland–Scotland Ridge, where dense aggregations of overwintering copepods were encountered during field surveys. The particle tracking model predicted that the major routes for the spring Calanus invasion into the North Sea were the East of Shetland Atlantic Inflow and the Norwegian Trench Atlantic Inflow, which agreed with seasonal trends observed in Continuous Plankton Recorder data. Overall, despite its relative simplicity, particle tracking was confirmed as a robust tool to explore the causal mechanisms behind the annual invasion of the North Sea by C. finmarchicus emerging from diapause in the deep waters off the Scottish continental shelf.     

Confirmation of the spawning area of the striped marlin, Tetrapturus audax, in the so-called core area of the eastern tropical Pacific off Mexico

We report the presence of striped marlin larvae in coastal waters of the mouth of the Gulf of California, collected during seven oceanographic cruises during 1990 to 1993. From 169 sampled stations, 30 produced a total of 68 larvae of 2.4–30.5 mm total length. Most of the larvae were about 3 mm, indicating a recent spawn. The sea surface temperature at the sampled stations ranged from 19.4°C to 32.0°C, but larvae were caught at stations with temperatures between 27.8°C and 31.5°C. These results clarify the existence of a spawning area of striped marlin in the eastern Pacific, located closer to the coast than previously believed, during several months of the year.