Patterns of rarity and taxonomic group size in plants

The objective of this research is to examine the extent to which phylogenetic and geographical drivers of rarity may interact to help us better predict distributions of rare taxa. This information is useful to conservation biologists when considering plans for the effective capture of biological diversity within reserve systems. We use 33 floras, distributed globally among five biomes, to assess pattern of rarity across taxonomic group size for plants. We show that small plant families (1-10 taxa) contain consistently fewer rare taxa than expected, while rare plants are proportionately over-represented in large plant families (>100 taxa). We also examine the distribution of species within families. The degree to which species are inequitably distributed among families varied systematically across floristic biomes. Mediterranean floras, in particular, are characterized by a greater than expected fraction of their species pool concentrated within large families, suggesting a high propensity for rarity simply by virtue of having a higher proportion of their constituent taxa within groups with a high likelihood of rarity. Finally, an analysis of a suite of floras using a common system of identifying rarity shows that the fraction of species within floras that are rare is predicted both by flora size and by a general metric (the Gini coefficient) of inequality among family sizes. Together, these patterns suggest a high degree of predictability in the distribution of rarity in plants that may reflect underlying natural speciation and extinction processes.     

Factors affecting performance response of pigs exposed to different challenge models: a multivariate approach

Factors associated with the severity with which different challenge models (CMs) compromise growth performance in pigs were investigated using hierarchical clustering on principal components (HCPC) analysis. One hundred seventy-eight studies reporting growth performance variables (average daily gain [ADG], average daily feed intake [ADFI], gain:feed [GF], and final body weight [FBW]) of a Control (Ct) vs. a Challenged (Ch) group of pigs using different CMs (enteric [ENT], environmental [ENV], lipopolysaccharide [LPS], respiratory [RES], or sanitary condition [SAN] challenges) were included. Studies were grouped by similarity in performance in three clusters (C1, C2, and C3) by HCPC. The effects of CM, cluster, and sex (males [M], females [F], mixed [Mi]) were investigated. Linear (LRP) and quadratic (QRP) response plateau models were fitted to assess the interrelationships between the change in ADG (∆ADG) and ADFI (∆ADFI) and the duration of challenge. All variables increased from C1 through C3, except for GF, which decreased (P < 0.05). LPS was more detrimental to ADG than ENV, RES, and SAN models (P < 0.05). Furthermore, LPS also lowered GF more than all the other CMs (P < 0.05). The ∆ADG independent of ∆ADFI was significant in LPS and SAN (P < 0.05), showed a trend toward the significance in ENT and RES (P < 0.10), and was not significant in ENV (P > 0.10), while the ∆ADG dependent on ∆ADFI was significant in ENT, ENV, and LPS only (P < 0.05). The critical value of ∆ADFI influencing the ∆ADG was significant in pigs belonging to C1 (P < 0.05) but not C2 or C3 (P > 0.10). The ∆ADG independent of duration post-Ch (irreparable portion of growth) was significant in C1 and C2 pigs, whereas the ∆ADFI independent of duration post-Ch (irreparable portion of feed intake) was significant in C1 pigs only (P < 0.05). Moreover, the time for recovery of ADG and ADFI after Ch was significant in pigs belonging to C1 and C2 (P < 0.05). Control F showed reduced ADG compared with Ct-M, and Ch-F showed reduced ADFI compared with Ch-M (P < 0.05). Moreover, the irreparable portion of ΔADG was 4.8 higher in F (−187.7; P < 0.05) compared with M (−39.1; P < 0.05). There are significant differences in growth performance response to CM based on cluster and sex. Furthermore, bacterial lipopolysaccharide appears to be an appropriate noninfectious model for immune stimulation and growth impairment in pigs.     

Productivity and nutritional value of BRS capiaçu grass (Pennisetum purpureum) managed at four regrowth ages in a semiarid region

Tropical Animal Health and Production - The objective of this study was to evaluate the productivity, productive efficiency, and nutritional value of the elephant grass cultivar BRS capiaçu...     

Effect of delipidant agents during in vitro culture on the development,lipid content,gene expression and cryotolerance of bovine embryos

In vitro produced embryos are still sensitive to the freezing process which can be explained, in part, by the high-lipid accumulation that characterizes these embryos. Therefore, we aimed to evaluate the effect of delipidating agents, L-carnitine and the trans-10 cis-12 conjugated linoleic acid (CLA) isomer, on blastocyst development, lipid content, gene expression and cryotolerance when added to embryo culture media. Embryos were cultured in four different media: T1: control (n = 616), synthetic oviduct fluid (SOF) media with 5% foetal bovine serum (FBS); T2: L-carnitine (n = 648), SOF medium with 5% FBS and 0.6 mg/ml of L-carnitine; T3: CLA (n = 627), SOF medium with 5% FBS and 100 μM trans-10 cis-12 CLA; and T4: L-carnitine + CLA: (n = 597), SOF medium with 5% FBS plus 0.6 mg/ml L-carnitine and 100 μM trans-10 cis-12 CLA. Supplementation of culture medium with either or both delipidating agents reduced (p < .05) blastocyst rate on D7 (T1 = 49 ± 3.5; T2 = 39 ± 3.0; T3 = 42 ± 3.9 and T4 = 39 ± 3.9), but did not affected gene expression (p > .05). Although embryos cultured in the presence of L-carnitine contained fewer (p < .05) lipid droplets than the control embryos, they showed a lower re-expansion rate 24 hr post-thaw than those (p < .05). In conclusion, although L-carnitine reduced the amount of lipids in cultured embryos, the use of L-carnitine and CLA during in vitro culture was not able to improve the embryo production and the response to cryopreservation.     

Ovum pick-up and in vitro maturation in spotted paca (Cuniculus paca—Linnaeus, 1766)

We tested FSHp, eCG and FSHp + eCG to establish ovum pick-up (OPU) and in vitro maturation method in spotted paca. Eight healthy adult females were subjected to each of four treatments to stimulate ovarian follicular growth. All females were subjected to a hormonal protocol using a single dose of 45 mg of injectable progesterone and single intramuscular injection of 0.075 mg d-cloprostenol on day 6. Ovarian stimulation was carried out as follows: in Group TFE (FSHp and eCG), animals were treated with a single dose of 80 mg of FSHp and 200 IU of eCG intramuscularly on day 6 after the application of progesterone; in Group TF (FSHp), they were treated with a single dose of 80 mg of FSHp intramuscularly on day 6 after application of progesterone; in Group treatment eCG, they were treated with 200 IU of eCG intramuscularly on day 6 after application of progesterone; and in Group TC (saline solution), 1 ml of saline solution was administered to control does. The OPU was performed between 22 and 26 hr after gonadotropin treatments. All recovered oocytes were placed into maturation media and incubated for 24 hr. There were no differences among the mean number of observed follicles, aspirated follicles and oocytes recovered per treatment. Oocyte maturation rates did not differ among groups, except, TF and treatment eCG oocytes had greater maturation rates than TC oocytes. In this study, gonadotropin administration failed to superovulate treated does and increase oocyte retrieval efficiency. Despite the feasibility of the procedure, further studies are needed to develop and refine hormonal protocols for oocyte recovery and in vitro maturation in this species.     

Inclusion of β-1,3/1,6-glucan in the ornamental fish,Jewel tetra (Hyphessobrycon eques), and its effects on growth,blood glucose,and intestinal histology

The effects of β-1,3/1,6-glucan on Hyphessobrycon eques were assessed after 42 days of feeding diets containing 0 (control group given commercial feed), 0.5, 1, or 2 g β-glucan/kg diet. In total, 180 fish, with an initial weight of 0.43?±?0.03 g, were used. There were 15 fish in each of twelve 42-L aquariums, and there were 3 aquariums of fish for each dietary treatment. The fish were fed until apparent satiety. Performance parameters (final weight, total length, standard length, feed intake, survival rate, weight gain, feed conversion, specific growth rate, and condition factor) and plasma glucose concentration were measured. Histological analysis of the proximal portion of the intestine (width and height of the villi, depth of the crypts, height of the enterocytes, thickness of the muscle layer, and number of goblet cells) was performed. Different levels of the additive did not influence fish performance (for example, final weight: control: 0.63 g, 0.5: 0.60, 1: 0.58, and 2: 0.61). Likewise, there was no influence on the plasma glucose concentration (control: 81.80 mg/dL, 0.5: 75.33, 1: 85.00, and 2: 81.00) and intestinal morphometry of the animals. However, the results showed that 2.0 g/kg of β-1,3/1,6-glucan provided a greater abundance of goblet cells secreting acidic and neutral mucus present in the epithelium (periodic acid-Schiff: 66.67 cells, Alcian blue pH 1.0: 72,67 cells, and Alcian blue pH 2.5: 95.00 cells), showing significant differences when compared to animals in the control group, which may represent better protection of the intestinal epithelium of H. eques.

     

Effect of the interaction between body weight and temperature on growth and maximum daily food intake in sharpsnout sea bream (<Emphasis Type="Italic">Diplodus puntazzo</Emphasis>)

In experimental culture conditions in tanks, the effect of weight (W: 11–452 g) and temperature (T: 14–29°C) on the growth rate (SGR, % bw day⁻¹) and maximum daily food intake (SFR, % bw day⁻¹) in sharpsnout sea bream (Diplodus puntazzo) was studied. The possible combined effect of both independent variables (W and T) was also analyzed by multiple regression analysis, fitting the data to the equation Ln Y = Ln a + b Ln W + cT + dT ² + eT Ln W. Both SGR and SFR, and therefore feed efficiency (FE = SGR/SFR), were significantly influenced by the interaction between temperature and weight and may be expressed by means of the following equations: Ln SGR = −6.1705 + 0.5809T − 0.0087T ² − 0.0249T Ln W ( R_\textadj² R_{\text{adj}}^{2}  = 0.949; ANOVA P < 0.0001); Ln SFR = −4.8257 + 0.4425T − 0.0063T ² − 0.0163T Ln W ( R_\textadj² R_{\text{adj}}^{2}  = 0.964; ANOVA P < 0.0001).The results suggest that the optimum temperature for SGR and FE (T _SGRopt and T _FEopt), and the temperature at which the maximum SFR (T _SFRmax) is reached, decreases with body weight, in accordance with the equations: T _SGRopt = 33.297 − 1.435 Ln W; T _FEopt = 29.332 − 1.890 Ln W; and T _SFRmax = 34.941 − 1.304 Ln W, respectively. In this way, T _SGRopt is 28.4, 26.7, and 24.7°C; T _SFRmax is 30.5, 28.9, and 27.1°C and T _FEopt is 22.9, 20.6, and 18°C for 30, 100 and 400 g body weight, respectively.     

Multinomial logit estimation of a diameter growth matrix model of two Mediterranean pine species in Spain

• Introduction   

Understanding diameter growth of the Mediterranean pine species is fundamental for evaluating and making appropriate strategic decisions in forest management. A matrix diameter growth model for two Mediterranean pine forest ecosystems in Spain has been developed.     

Effects of shrub and canopy cover on the relative growth rate of <Emphasis Type="Italic">Pinus pinaster</Emphasis> Ait. seedlings of different sizes

• Introduction   

Shrubs are recognized as important tree regeneration niches. In this study, we experimentally analysed the effects of shrub presence, canopy cover (closed cover and open cover-gaps), and seedling size on Pinus pinaster growth.