Characterization of RD114-related endogenous cat retroviral elements ECE2

RD114 virus is an endogenous xenotropic Type C retrovirus of domestic cat. Previously, it had been shown that genomic DNA of cat contained approximately 20 copies of RD114-related sequences. Only one encoded for the replication-competent RD114 virus. The endogenous sequences exhibited substantial sequence conservation within the gag and pol genes and LTRs, but were characterized by deletions and substitutions within the env region. The endogenous cat retroviral element ECE2 was isolated by screening a genomic DNA library of cat liver DNA with an env-specific cDNA of RD114 virus. It contained an env region which differed from all RD114-related sequences so far isolated and was homologous to the corresponding region of replication-competent RD114 with regard to their restriction map and partial sequence analysis (p20). Otherwise, ECE2 had a deletion of approximately 1 kbp in the putative pol gene and, therefore, did not represent the locus of inducible RD114 virus.     

Histopathological changes in myxosomosis in rainbow trout

Rainbow trout, caught in a pond 25, 45 and 48 days from releasing, were studied for histopathological changes. Protozoan activity destroys the basal matter of the hypertrophic cartilage. The chondral tissue around plasmodium reacts by showing an increased basophilia and by chondrocytal reaction. The plasmodia tend to spread spherically, but the spreading is prevented by compact bone, connective tissue, or hardened cartilage with flattened chondrocytes. One host can bear one plasmodium or more plasmodia, up to the possibility of a generalized process. The host organism reacts to the destructive changes caused by the protozoan by letting its connective tissue cells grow into the cavities produced by the protozoan, into the plasmodia of the protozoan and into the destruction line; thus the protozoan is separated from the nutrition base. The connective tissue enters the lesion via a hole in compact bone or via a fissure between bone and cartilage. Circulation and blood elements were not found to be present in the penetrating connective tissue. The bone tissue reacts to the presence of the protozoan by thickening the periosteum. Mature spores in the lesions by the protozoan are reduced with host age.     

Cutaneous manifestations of neurological diseases: review of neuro-pathophysiology and diseases causing pruritus

Pruritus does not always originate from stimulation to the skin associated with primary dermatological disorders. It may be caused by neurological or behavioural disorders. The essential role of the nervous system in the control (enhancement and inhibition) of pruritus and its pathophysiology are presented. In order to allow differentiation between dermatological and neurological disorders, inherited or acquired peripheral neuropathies and central nervous disorders (Arnold-Chiari syndrome, seizure-related disorders, central nervous system tumours) that may induce itch are discussed.     

The effect of litter materials on broiler performance: a systematic review and meta-analysis

ABSTRACT

1. Divergence in outcomes from studies on the effects of litter materials on body weight, feed intake, feed conversion and mortality in broilers has led to a need for a meta-analysis to quantify their effects.

2. A systematic search of published quantitative research relating to wood shavings and alternative bedding litters was conducted using databases.

3. Means, standard deviations and sample sizes were extracted from each study. The response variables were analysed using the standardised mean difference (SMD, control treatment minus alternative litters).

4. The literature demonstrated that alternative materials have no impact on feed intake in broilers, compared to wood shavings (SMD = 0.064, 95% CI = ?0.101–0.229, P = 0.44).

5. There was a positive overall effect of wood shavings on body weight (SMD = 0.253, 95% CI = 0.073–0.433, P = 0.006), feed conversion (SMD = ?0.169, 95% CI = ?0.327 – ?0.012, P = 0.03) and mortality (SMD = ?1.069, 95% CI = ?1.983 – ?0.155, P = 0.02) of broilers, compared to other litter types.

6. Subgroup meta-analysis revealed that straw, when used as an alternative litter material to wood shavings, may be responsible for lower body weight (SMD = 0.654, 95% CI = 0.162–1.146, P = 0.009), worse feed conversion (SMD = ?0.487, 95% CI = ?0.828 – ?0.145, P = 0.005) and higher mortality rates of broilers (SMD = ?3.25, 95% CI = ?5.681 – ?0.819, P = 0.009). Rice husks impaired body weight compared to wood shavings (SMD = 0.535, 95% CI = 0.065–1.004, P = 0.02).

7. It was concluded that different litter types do not affect the broilers’ feed intake. Conversely, broilers kept on straw showed lower body weights, worse feed conversion and higher mortality rates, in comparison to wood shavings. Rice husks decreased body weight compared to wood shavings.     

Soil aggregate stability and aggregate-associated organic carbon under different land use or land cover types

Soil aggregate stability (SAS) is an indicator for soil condition and is greatly influenced by land use or land cover (LULC) type and other soil and environmental attributes. This study investigated the soil aggregate-size distribution, SAS, aggregate-associated organic carbon (AAOC) and the relative importance of factors affecting SAS and AAOC. Based on conditioned Latin hypercube sampling, soil aggregate samples were collected from the “A” horizon and wet sieved into large macroaggregates (>2.0 mm), small macroaggregates (0.25–2.0 mm), microaggregates (0.053–0.25 mm) and mineral fraction (<0.053 mm). The large macroaggregates accounted for 86% to 93% of the total aggregates under all LULC types except under dry land (64%) and paddy land (35%). The SAS under different LULC decreased in the order fir > shrubland > natural grassland > orchard > blue pine > broadleaf > mixed conifer > dry land > paddy land. The AAOC of the large macroaggregates constituted for 76%–90% of the total AAOC under all LULC types except under dry land (65%) and paddy land (38%). While SAS was largely influenced by the AAOC of small macroaggregates, microaggregates and large macroaggregates and LULC type, the AAOC of different aggregate fractions was mostly affected by LULC type, altitude and slope. SAS did not exhibit any significant relationship with the AAOC of different aggregate fractions under the natural LULC types but showed a strong relationship under the agricultural land indicating that AAOC is more critical for SAS under the agricultural land than under the natural LULC.     

Modeling the long-term natural regeneration potential of woodlands in semi-arid regions to guide restoration efforts

Understanding forest regeneration at sites previously used for agriculture underlies the establishment of science-based woodlands management policies. This is especially relevant in semi-arid areas, where the tree cover is critical in ameliorating the effects of aridity and in preventing desertification and land degradation. Natural regeneration in semi-arid areas occurs very slowly, which in part explains why it has hardly been studied. In the present work, we sought to devise a method to predict the natural regeneration potential of woodlands in semi-arid areas, to be used in guiding restoration efforts. Specifically, we evaluated holm oak coverage at a long-term ecological research site and then designed and validated a model to predict the natural regeneration of holm oak based on a few environmental variables. Unlike available studies, we obtained long-term information on tree regeneration (making use of >60 years of aerial photography) and climate (using long-term climate and microclimate data). We found that microclimate, measured using the potential solar radiation as a proxy, was a key driver of natural regeneration: after 60 years of agricultural abandonment, less sun-exposed areas attained a tree cover >90 %, whereas in more sun-exposed areas it remained below 20 %. We then used the model to map the natural regeneration potential, first in the study area and then in an area where holm oak plantations had been unsuccessfully introduced. In the latter case, the model successfully predicted the failure of this reforestation effort. Our results support the use of this model by decision makers to optimize management practices, as it will encourage the concentration of efforts in areas more prone to successful reforestation and allow the identification of areas more likely to benefit from natural regeneration processes.     

A molecular jump mechanism of water reorientation

Despite long study, a molecular picture of the mechanism of water reorientation is still lacking. Using numerical simulations, we find support for a pathway in which the rotating water molecule breaks a hydrogen bond (H-bond) with an overcoordinated first-shell neighbor to form an H-bond with an undercoordinated second-shell neighbor. The H-bond cleavage and the molecular reorientation occur concertedly and not successively as usually considered. This water reorientation mechanism involves large-amplitude angular jumps, rather than the commonly accepted sequence of small diffusive steps, and therefore calls for reinterpretation of many experimental data wherein water rotational relaxation is assumed to be diffusive.