Erosão na cultura do milho em sucessão à aveia preta e pousio descoberto, em preparo convencional e plantio direto, com tração animal e tratorizada

Empregando chuva simulada em Argissolo Vermelho distrófico arênico, com declividade média de 0,12 m m-1, avaliou-se a erosão na cultura do milho (Zea mays L.) em preparo convencional e plantio direto, utilizando tração animal e tratorizada, antecedida de pousio descoberto e aveia preta (Avena strigosa Schieb) no inverno, no período compreendido entre 1994 e 1995. Chuvas simuladas na intensidade de 64 mm h-1 e duração de 60 a 105 min foram aplicadas em quatro épocas: logo após a semeadura, 30 e 60 dias após a emergência e logo após a colheita do milho. A cobertura do solo propiciada pela cultura de inverno foi reduzida em 90% após o preparo convencional, independentemente da forma de tração. As perdas de solo e água medidas durante o desenvolvimento do milho foram sempre maiores sob preparo convencional do que sob plantio direto, independentemente da forma de tração, exceto logo após a colheita, quando a resteva estava uniformemente distribuída na superfície do solo. No preparo convencional, a erosão na cultura do milho foi, na média das formas de tração, 45% menor, quando antecedida de aveia preta no inverno do que quando antecedida de pousio descoberto. Por sua vez, a cultura do milho, por si só, reduziu a erosão em 60%, na média das formas de tração, comparada à do solo descoberto. A forma de tração influenciou a erosão somente no preparo convencional, com a animal apresentando perdas totais de solo 55 e 15% inferiores à tratorizada, respectivamente na cultura do milho e em solo descoberto. A perda de água por enxurrada foi mais afetada pela forma de tração no preparo convencional, totalizando, em média, 44% na animal e 57% na tratorizada, em relação ao volume total de chuva aplicado.

Aqueous dynamic and histological findings after deep sclerectomy with collagen implant in an animal model.

AIM: The use of an animal model to study the aqueous dynamic and the histological findings after deep sclerectomy with (DSCI) and without collagen implant. METHODS: Deep sclerectomy was performed on rabbits' eyes. Eyes were randomly assigned to receive collagen implants. Measurements of intraocular pressure (IOP) and aqueous outflow facility using the constant pressure method through cannulation of the anterior chamber were performed. The system was filled with BSS and cationised ferritin. Histological assessment of the operative site was performed. Sections were stained with haematoxylin and eosin and with Prussian blue. Aqueous drainage vessels were identified by the reaction between ferritin and Prussian blue. All eyes were coded so that the investigator was blind to the type of surgery until the evaluation was completed. RESULTS: A significant decrease in IOP (p<0.05) was observed during the first 6 weeks after DSCI (mean IOP was 13.07 (2.95) mm Hg preoperatively and 9.08 (2.25) mm Hg at 6 weeks); DS without collagen implant revealed a significant decrease in IOP at weeks 4 and 8 after surgery (mean IOP 12.57 (3.52) mm Hg preoperatively, 9.45 (3.38) mm Hg at 4 weeks, and 9.22 (3.39) mm Hg at 8 weeks). Outflow facility was significantly increased throughout the 9 months of follow up in both DSCI and DS groups (p<0.05). The preoperative outflow facility (OF) was 0.15 (0.02) micro l/min/mm Hg. At 9 months, OF was 0.52 (0.28) microl/min/mm Hg and 0.46 (0.07) micro l/min/mm Hg for DSCI and DS respectively. Light microscopy studies showed the appearance of new aqueous drainage vessels in the sclera adjacent to the dissection site in DSCI and DS and the apparition of spindle cells lining the collagen implant in DSCI after 2 months. CONCLUSION: A significant IOP decrease was observed during the first weeks after DSCI and DS. DS with or without collagen implant provided a significant increase in outflow facility throughout the 9 months of follow up. This might be partly explained by new drainage vessels in the sclera surrounding the operated site. Microscopic studies revealed the appearance of spindle cells lining the collagen implant in DSCI after 2 months.

Reproductive and post-reproductive life history of wild-caught Drosophila melanogaster under laboratory conditions.

The life history of the fruit fly (Drosophila melanogaster) is well understood, but fitness components are rarely measured by following single individuals over their lifetime, thereby limiting insights into lifetime reproductive success, reproductive senescence and post-reproductive lifespan. Moreover, most studies have examined long-established laboratory strains rather than freshly caught individuals and may thus be confounded by adaptation to laboratory culture, inbreeding or mutation accumulation. Here, we have followed the life histories of individual females from three recently caught, non-laboratory-adapted wild populations of D. melanogaster. Populations varied in a number of life-history traits, including ovariole number, fecundity, hatchability and lifespan. To describe individual patterns of age-specific fecundity, we developed a new model that allowed us to distinguish four phases during a female's life: a phase of reproductive maturation, followed by a period of linear and then exponential decline in fecundity and, finally, a post-ovipository period. Individual females exhibited clear-cut fecundity peaks, which contrasts with previous analyses, and post-peak levels of fecundity declined independently of how long females lived. Notably, females had a pronounced post-reproductive lifespan, which on average made up 40% of total lifespan. Post-reproductive lifespan did not differ among populations and was not correlated with reproductive fitness components, supporting the hypothesis that this period is a highly variable, random 'add-on' at the end of reproductive life rather than a correlate of selection on reproductive fitness. Most life-history traits were positively correlated, a pattern that might be due to genotype by environment interactions when wild flies are brought into a novel laboratory environment but that is unlikely explained by inbreeding or positive mutational covariance caused by mutation accumulation.

Animal Tissue Response To Mid-Term Electronic Modular Artificial Sphincter Implantation

Introduction and objectives: The AMS 800TM is considered the gold standard for sphincter replacement. However, the one-ring design can erode the urethra and lead to severe complications. A mechanism that could alternatively compress successive segments of the urethra would limit such deleterious outcome. We report 12 weeks animal urethral tissue analysis following implantation of a new modular artificial sphincter. METHODS: The device is composed by three parts: the contractile unit, two rings and an integrated microprocessor. The contractile unit is made of Nitinol fibers. The rings are placed around the urethra to control the flow of urine by squeezing the urethra. They work in a sequential alternative mode and are controlled by a microprocessor connected to an external computer. The computer can reveal specific failure of device components. The device was impkanted in eight male sheep. The rings were positioned around the urethra and the control unit was placed 5cm away. The device was working twenty hours per day; it was open 10min. per hour to allow urination. The animals were sacrificed after 12 weeks. The urethra and the tissues surrounding the control unit were macroscopically and microscopically examined. Two transversal sections crossing the sphincter and two transversal sections crossing the urethra alone were obtained and stained with modified Paragon after resin embedding. Urethra was also embedded in paraffin. The first section was stained with safranin-hematoxylin-eosin, the second section was stained with Masson's Trichrome and the remaining eight sections were available for immunolabelling of the macrophages.Results: The chronic study went uneventful. No clinical infection or pain was observed. The computer registered no specific failure in ring function, Nitinol wires and tube connectors. At explantation, except for a slight grade of lymphocytes in two out of eight specimens, no urethral stricture or atrophy could be observed. Immunohistochemistry confirmed the absence of macrophages. Tissue structure and organization of the urethra with and without artificial sphincter were similar. No migration of the device was observed.Conclusions: The study clearly showed no tissue damage or inflammation of the urethra. Electronic design, preservation of urethral vascularisation and adjustability after implantation are the key ideas to improve the actual AUS. Further studies will be carried out to evaluate this potential.

Native homing endonucleases can target conserved genes in humans and in animal models.

In recent years, both homing endonucleases (HEases) and zinc-finger nucleases (ZFNs) have been engineered and selected for the targeting of desired human loci for gene therapy. However, enzyme engineering is lengthy and expensive and the off-target effect of the manufactured endonucleases is difficult to predict. Moreover, enzymes selected to cleave a human DNA locus may not cleave the homologous locus in the genome of animal models because of sequence divergence, thus hampering attempts to assess the in vivo efficacy and safety of any engineered enzyme prior to its application in human trials. Here, we show that naturally occurring HEases can be found, that cleave desirable human targets. Some of these enzymes are also shown to cleave the homologous sequence in the genome of animal models. In addition, the distribution of off-target effects may be more predictable for native HEases. Based on our experimental observations, we present the HomeBase algorithm, database and web server that allow a high-throughput computational search and assignment of HEases for the targeting of specific loci in the human and other genomes. We validate experimentally the predicted target specificity of candidate fungal, bacterial and archaeal HEases using cell free, yeast and archaeal assays.

Gain of function mutations in CgPDR1 of Candida glabrata not only mediate antifungal resistance but also enhance virulence.

CgPdr1p is a Candida glabrata Zn(2)-Cys(6) transcription factor involved in the regulation of the ABC-transporter genes CgCDR1, CgCDR2, and CgSNQ2, which are mediators of azole resistance. Single-point mutations in CgPDR1 are known to increase the expression of at least CgCDR1 and CgCDR2 and thus to contribute to azole resistance of clinical isolates. In this study, we investigated the incidence of CgPDR1 mutations in a large collection of clinical isolates and tested their relevance, not only to azole resistance in vitro and in vivo, but also to virulence. The comparison of CgPDR1 alleles from azole-susceptible and azole-resistant matched isolates enabled the identification of 57 amino acid substitutions, each positioned in distinct CgPDR1 alleles. These substitutions, which could be grouped into three different "hot spots," were gain of function (GOF) mutations since they conferred hyperactivity to CgPdr1p revealed by constitutive high expression of ABC-transporter genes. Interestingly, the major transporters involved in azole resistance (CgCDR1, CgCDR2, and CgSNQ2) were not always coordinately expressed in presence of specific CgPDR1 GOF mutations, thus suggesting that these are rather trans-acting elements (GOF in CgPDR1) than cis-acting elements (promoters) that lead to azole resistance by upregulating specific combinations of ABC-transporter genes. Moreover, C. glabrata isolates complemented with CgPDR1 hyperactive alleles were not only more virulent in mice than those with wild type alleles, but they also gained fitness in the same animal model. The presence of CgPDR1 hyperactive alleles also contributed to fluconazole treatment failure in the mouse model. In conclusion, this study shows for the first time that CgPDR1 mutations are not only responsible for in vitro/in vivo azole resistance but that they can also confer a selective advantage under host conditions.

Animal Industry News, 2010, Vol. 11, no. 1

Newsletter produced by Department of Agriculture and Land Stewardship about the animal industry in Iowa.

Experimental cerebral malaria develops independently of caspase recruitment domain-containing protein 9 signaling.

The outcome of infection depends on multiple layers of immune regulation, with innate immunity playing a decisive role in shaping protection or pathogenic sequelae of acquired immunity. The contribution of pattern recognition receptors and adaptor molecules in immunity to malaria remains poorly understood. Here, we interrogate the role of the caspase recruitment domain-containing protein 9 (CARD9) signaling pathway in the development of experimental cerebral malaria (ECM) using the murine Plasmodium berghei ANKA infection model. CARD9 expression was upregulated in the brains of infected wild-type (WT) mice, suggesting a potential role for this pathway in ECM pathogenesis. However, P. berghei ANKA-infected Card9(-/-) mice succumbed to neurological signs and presented with disrupted blood-brain barriers similar to WT mice. Furthermore, consistent with the immunological features associated with ECM in WT mice, Card9(-/-) mice revealed (i) elevated levels of proinflammatory responses, (ii) high frequencies of activated T cells, and (iii) CD8(+) T cell arrest in the cerebral microvasculature. We conclude that ECM develops independently of the CARD9 signaling pathway.

Sustainability - a challenge to animal production and breeding

Selostus: Kestävän kehityksen vaatimukset kotieläintuotannossa ja -jalostuksessa

Activation of peroxisome proliferator-activated receptor beta/delta inhibits lipopolysaccharide-induced cytokine production in adipocytes by lowering nuclear factor-kappaB activity via extracellular signal-related kinase 1/2.

OBJECTIVE: Chronic activation of the nuclear factor-kappaB (NF-kappaB) in white adipose tissue leads to increased production of pro-inflammatory cytokines, which are involved in the development of insulin resistance. It is presently unknown whether peroxisome proliferator-activated receptor (PPAR) beta/delta activation prevents inflammation in adipocytes. RESEARCH DESIGN AND METHODS AND RESULTS: First, we examined whether the PPARbeta/delta agonist GW501516 prevents lipopolysaccharide (LPS)-induced cytokine production in differentiated 3T3-L1 adipocytes. Treatment with GW501516 blocked LPS-induced IL-6 expression and secretion by adipocytes and the subsequent activation of the signal transducer and activator of transcription 3 (STAT3)-Suppressor of cytokine signaling 3 (SOCS3) pathway. This effect was associated with the capacity of GW501516 to impede LPS-induced NF-kappaB activation. Second, in in vivo studies, white adipose tissue from Zucker diabetic fatty (ZDF) rats, compared with that of lean rats, showed reduced PPARbeta/delta expression and PPAR DNA-binding activity, which was accompanied by enhanced IL-6 expression and NF-kappaB DNA-binding activity. Furthermore, IL-6 expression and NF-kappaB DNA-binding activity was higher in white adipose tissue from PPARbeta/delta-null mice than in wild-type mice. Because mitogen-activated protein kinase-extracellular signal-related kinase (ERK)1/2 (MEK1/2) is involved in LPS-induced NF-kappaB activation in adipocytes, we explored whether PPARbeta/delta prevented NF-kappaB activation by inhibiting this pathway. Interestingly, GW501516 prevented ERK1/2 phosphorylation by LPS. Furthermore, white adipose tissue from animal showing constitutively increased NF-kappaB activity, such as ZDF rats and PPARbeta/delta-null mice, also showed enhanced phospho-ERK1/2 levels. CONCLUSIONS: These findings indicate that activation of PPARbeta/delta inhibits enhanced cytokine production in adipocytes by preventing NF-kappaB activation via ERK1/2, an effect that may help prevent insulin resistance.

OpenFluDB, a database for human and animal influenza virus.

Although research on influenza lasted for more than 100 years, it is still one of the most prominent diseases causing half a million human deaths every year. With the recent observation of new highly pathogenic H5N1 and H7N7 strains, and the appearance of the influenza pandemic caused by the H1N1 swine-like lineage, a collaborative effort to share observations on the evolution of this virus in both animals and humans has been established. The OpenFlu database (OpenFluDB) is a part of this collaborative effort. It contains genomic and protein sequences, as well as epidemiological data from more than 27,000 isolates. The isolate annotations include virus type, host, geographical location and experimentally tested antiviral resistance. Putative enhanced pathogenicity as well as human adaptation propensity are computed from protein sequences. Each virus isolate can be associated with the laboratories that collected, sequenced and submitted it. Several analysis tools including multiple sequence alignment, phylogenetic analysis and sequence similarity maps enable rapid and efficient mining. The contents of OpenFluDB are supplied by direct user submission, as well as by a daily automatic procedure importing data from public repositories. Additionally, a simple mechanism facilitates the export of OpenFluDB records to GenBank. This resource has been successfully used to rapidly and widely distribute the sequences collected during the recent human swine flu outbreak and also as an exchange platform during the vaccine selection procedure. Database URL: http://openflu.vital-it.ch.

Effects of composite casein and [beta]-lactoglobulin genotypes on renneting properties and composition of bovine milk by assuming an animal model

Selostus: Kaseiinien yhdistelmägenotyyppien ja [beta]-laktoglobuliinin genotyyppien vaikutus maidon juoksettumisominaisuuksiin ja koostumukseen

Distribuição e caracterização de substâncias húmicas em vermicompostos de origem animal e vegetal

A utilização de resíduos orgânicos, como fertilizantes e condicionadores de solo, requer sua maturação e monitoramento da qualidade do material resultante. A vermicompostagem é uma técnica que, ao longo do processo, elimina os potenciais efeitos adversos dos resíduos à saúde humana e ao solo. A avaliação das substâncias húmicas (SH) nos produtos finais quanto à quantidade e à qualidade permite inferir sobre o grau de estabilidade e maturidade dos vermicompostos. Este trabalho objetivou avaliar a qualidade de seis vermicompostos das seguintes matérias-primas: esterco bovino (EB), esterco ovino (EO), esterco suíno (ES), esterco de codorna (EC), borra de café (BC) e de erva-mate (BE) com respeito ao teor de ácidos húmicos (AH) e de ácidos fúlvicos (AF) e às suas características químicas, após 70 dias de compostagem. O fracionamento químico da matéria orgânica foi realizado com base na solubilidade em meio básico e ácido e a distribuição de cada fração calculada como percentual do C total. Foram calculados os índices de humificação: percentual de AH e razão AH/AF. Nos AH e AF purificados, determinaram-se a composição elementar (CHNO), a composição química por espectroscopia de infravermelho com transformada de Fourier (FTIR) e o índice de aromaticidade I1630/I2920. O teor de substâncias húmicas (AH+AF) decresceu na seqüência: BC > EO≈ BE≈ EB > ES > EC, tendo sua composição química também diferido entre os vermicompostos. O grau de maturidade foi superior nos vermicompostos de resíduos de origem vegetal (borra de café e de erva-mate). Os AH desses dois vermicompostos apresentaram menor proporção de grupos oxigenados e menor caráter aromático.