Biophysical connectivity of snapper spawning aggregations and marine protected area management alternatives in Cuba

The ability of larvae to move beyond the spatial range of adult migrations can be critical to the resilience of populations that aggregate to spawn. We reviewed the literature and unpublished information on larval transport modeling, reef fish spawning aggregations, and marine protected area (MPA) management to identify alternatives for Cuban spawning site conservation. Larval transport information is available at annual and decadal scales for eight Cuban sites for five species of snappers. Connectivity patterns were examined: (a) within Cuban regions, (b) among Cuban regions, and (c) among other countries. We compared this information with the distribution of protected areas relative to spawning sites, site management attributes, and potential alternatives. Of eight focal spawning sites, seven are in protected areas and one is proposed. Southeast and north‐central Cuba had highest estimated within‐region retention levels. Southwest and northwest sites exported relatively more larvae out‐of‐region. Southern regions produced larvae that reached Jamaica, the Cayman Islands and Haiti. All northern regions can export larvae to the southern Bahamas. The regions and sites within are geomorphologically diverse with variable fishing and socio‐economic attributes. Information on stock status and protected area efficacy is limited and field assessments of aggregation status are needed for multispecies spawning sites. Few management plans address spawning conservation or network connectivity opportunities for MPAs. An alternative is development of one or more regional workgroups of protected area specialists, fishery scientists, expert fishers, and other stakeholders. Temporal closures of fisheries before and during spawning season could also amplify effectiveness of current gear‐ and zoning‐based management tools.     

Comparison of early splenic changes associated with replication of viruses in murine monocytic macrophages

An effect of replication of certain viruses in murine monocytic macrophages was manifested by depletion of cells through degenerative and necrotizing changes in thymus-dependent areas of lymphoid structures. In mice infected with murine hepatitis virus (MHV-3) or lactate dehydrogenase virus, these changes were transient in mice killed on postinoculation day (PID) 2. To study these morphologic changes due to viral replication, adult Swiss specific-pathogen-free homozygous nude mice (nu/nu) and their heterozygous haired littermates (nu/+) were inoculated with 10(5) LD50 of MHV-3, euthanatized, and necropsied on PID 1, 2, 4, 6, 8, and 10 along with noninoculated controls. The nu/+ and nu/nu mice killed on PID 2 had lymphocytic karyorrhexis and depletion of cells in the thymus-dependent area. In the heterozygote, these characteristic lesions were transient; whereas in the homozygote, lesions persisted and were present in survivors euthanatized and necropsied on PID 16. Although the intensity of lesions due to MHV-3 varied between nu/+ and nu/nu mice, virus titers determined on liver homogenates were similar for the homozygote and heterozygote during acute disease. Nude and nonnude mice given lactate dehydrogenase virus and killed on PID 2 had a transient depletion of lymphocytes; whereas mice given lymphocytic choriomeningitis virus and killed on PID 4 had a similar lesion. Lesions neither occurred when mice were treated with silica before inoculation, indicating that functional monocytic macrophages were required, nor occurred when another virus, herpes simplex virus type 1, was given.     

Detection of a pigeon pea witches'-broom-related phytoplasma in trees of Gliricidia sepium affected by little-leaf disease in Central America

The polymerase chain reaction (PCR) incorporating phytoplasma-specific ribosomal RNA primer pair P1 and P7 consistently amplified a product of expected size (1.8 kb) when template DNA for PCR was extracted from leaf and shoot samples of Gliricidia sepium from Honduras exhibiting symptoms of little-leaf disease (LLD). Restriction fragment length polymorphism analysis (RFLP) of amplified rDNA products indicated that phytoplasmas detected in LLD-affected G. sepium were very similar although not identical to phytoplasmas associated with pigeon pea witches'-broom (PPWB) disease in the western Caribbean region. Phytoplasma detection in trees was enhanced by reamplification of the P1/P7-primed PCR products with nested primers PPf1 and Tint. Nested reactions enabled additional positive detections in foliage of several G. sepium trees showing only mild or no apparent LLD symptoms. Neither rDNA RFLP nor sequence analyses of 16–23 S rRNA spacer regions revealed differences among Honduran LLD phytoplasma or between these strains and phytoplasmas detected in G. sepium with LLD-like symptoms in El Salvador, Guatemala, and Nicaragua, indicating that closely related, possibly identical, pathogens presently affect this tree species in all four countries.     

Protides of the Mustelidae: immunoresponse of mustelids to Aleutian mink disease virus.

Members of North American Mustelidae were tested for their response to inoculation with 10(6) infective doses of Aleutian disease virus. In subfamily Mustelinae, 3 species in the genus Mustela (M vision, M erminea, and M putorius) and 2 species in genus Martes (Ma pennanti and Ma americana) responded immunologically with some features resembling Aleutian disease in mink. In subfamily Mephitinae, only Mephitis mephitis responded, and others of the subfamily did not, nor did members of subfamilies Melinae and Lutrinae. The responses observed ranged from development of detectable antibody levels determined by counterimmunoelectrophoresis to histopathologic changes typical of Aleutian disease.     

Concentrations of Prolactin, LH, Testosterone, TSH and Thyroxine in Normospermic Dogs of Different Breeds

Concentrations of prolactin (PRL), LH, testosterone (T), TSH and thyroxine (T₄) were determined before and at 20, 120 and 180 min after a single iv injection of thyrotropin-releasing hormone (TRH) in eight Beagles, eight Fox Terriers, six Labrador Retrievers and five Great Danes that were normospermic. Mean basal PRL concentrations were lower in the Fox Terriers compared with the Great Danes (p < 0.05). Mean LH concentrations were higher in the Fox Terriers than in the Beagles, and T was lower in the Fox Terriers at some times but not others (p < 0.05). Thyroid Stimulating Hormone (TSH) concentrations did not differ among breeds, while mean basal T₄ values were lower in Fox Terriers compared with Labrador Retrievers and Great Danes (p < 0.05). Stimulation of T₄ secretion 120 and 180 min after iv TRH injection was most pronounced in the Beagles and less in the Fox Terriers (p < 0.05). The results of the present study indicate that potential breed differences in circulating concentrations of PRL, LH, T, TSH and T₄ in male dogs with apparently normal fertility can be encountered, but further studies are needed to determine whether the observed differences are typical features of these breeds, reflect subsets of dogs within breeds, or are in part because of possible uncontrolled parameters such as sample timing, ambient photoperiod, housing conditions or diet.     

Mutations that increase the life span of C. elegans inhibit tumor growth

Mutations in gld-1 cause lethal germline tumors in the nematode Caenorhabditis elegans. We find that a wide variety of mutations that extend C. elegans' life span confer resistance to these tumors. The long life spans of daf-2/insulin-receptor mutants were not shortened at all by gld-1 mutations; we attribute this finding to decreased cell division and increased DAF-16/p53-dependent apoptosis within the tumors. Mutations that increase life span by restricting food intake or inhibiting respiration did not affect apoptosis but reduced tumor cell division. Unexpectedly, none of these longevity mutations affected mitosis in normal germlines; this finding suggests that cellular changes that lead to longevity preferentially antagonize tumor cell growth.     

The stress caused by laparoscopy in sheep and its alleviation

AIM: To determine the plasma cortisol response to laparoscopy in ewes and investigate means of reducing it. METHODS: Ewes without lambs at foot (n=40) were subjected to one of three control or one laparoscopy treatments (n=10 ewes/treatment), being: no restraint or drugs; acepromazine maleate (ACP) control and no restraint; ACP and restraint in a cradle for 5 min; and laparoscopy following ACP. Additional ewes with lambs at foot (n=30) were subjected to: laparoscopy following ACP; laparoscopy following ACP and ketoprofen; and laparoscopy following detomidine. Drugs were injected 20 min before treatment, after a first blood sample had been taken. Blood samples were taken by jugular venepuncture from the ewes 20 min before treatment and at 20, 40, 60, 90, 120, 150 and 180 min after treatment, while all ewes were held in a pen. Plasma was harvested and assayed for its concentration of cortisol. RESULTS: Plasma cortisol concentrations (PCC) remained constant in ewes in the control restraint group for 80 min. In ewes given ACP, PCC increased for the first 20 min after treatment but then returned to pre-treatment concentrations. PCC of ewes given ACP and restrained in a cradle were elevated above pre-treatment concentrations for 90 min. PCC in ewes subjected to laparoscopy following sedation with ACP increased to a peak at 40 min and returned to pre-treatment concentrations after 60 (with lambs) or 120 (without lambs) min. When ACP and ketoprofen were given before laparoscopy, PCC peaked at 20 min and returned to pre-treatment concentrations by 40 min. PCC of ewes given detomidine before laparoscopy remained at pre-treatment concentrations throughout. PCC of ewes subjected to laparoscopy with ACP sedation only were greater than those of control restraint, ACP control, and ewes subjected to laparoscopy after being given ketoprofen or detomidine between 20 and 60 min after treatment. PCC of ewes subjected to laparoscopy were greater than those of control ewes placed in a cradle at 20 and 40 min. PCC of ewes given ketoprofen were lower than those of ewes subject to laparoscopy following ACP. CONCLUSIONS: Laparoscopy, even after sedation with ACP, caused some distress in ewes, as evidenced by increased plasma cortisol levels. Plasma cortisol response was alleviated by the administration of ketoprofen and eliminated by detomidine, probably because of both analgesic and sedative effects of the latter drug.     

Impacts of major health conditions affecting the Australian sheepmeat value chain: a review

Major health conditions in sheep contribute to substantial economic losses throughout the sheepmeat supply chain in Australia. A systematic review was undertaken to explore the measurable impact of six conditions: arthritis, sheep measles, pleurisy, pneumonia, grass seeds and rib fractures, on the production of lamb and mutton across the meat value chain. Peer‐reviewed scientific literature from three databases and non‐peer‐reviewed articles and reports from Australian government and non‐government websites were searched between 11 and 17 November 2019. Original articles, including studies conducted in Australia and New Zealand, that had measurable impacts on conditions of interest were included. The search yielded 16 articles and reports and were classified as producer impact and/or processor impact studies. Mortalities were quantified for pneumonia and arthritis, with pneumonia having the highest impact for producers. Grass seed infestation resulted in the highest impact on carcase and liveweight losses compared to arthritis and pneumonia. Arthritis had the highest trim weight losses for both lamb and mutton and the highest rate of carcase condemnation. Grass seed was the only condition where other impacts on the processor (chain speed and staff relocation to the boning room) were quantified. Although quantifiable production and processing losses were available for some conditions, this review has highlighted that limited quantifiable data based on scientifically sound research were not available for other conditions. The evidence for some conditions found in this review can be used to target future research activities and to further assist producers in making informed management decisions on prevention and control.     

The use of toltrazuril for the prevention of coccidiosis in piglets before weaning

SUMMARY: To determine the efficacy of toltrazuril as a prophylactic treatment for coccidiosis in piglets caused by Isospora suis (I suis) , a single 1.0 mL dose of toltrazuril was administered orally to 1056 piglets between 3 and 6 days of age, in 5 piggeries. Prophylactic treatment of piglets reduced the occurrence of coccidiosis in litters from 71% to 22%. The number of antibacterial treatments given and the number of piglets affected per litter were also significantly reduced, resulting in some improvement in growth rates to weaning. The severity of diarrhoea was significantly reduced, as was the amount of oocyst excretion. The number of days that piglets excreted oocysts in the faeces was reduced from 4.9 days to 2.5 days. The detection of J suis in piglets with diarrhoea was reduced from 84% in the untreated piglets to 6% in the piglets given the prophylactic treatment.