Design of nest access grids and perches in front of the nests: Influence on the behavior of laying hens.

In aviary systems for laying hens, it is important to provide suitable nest access platforms in front of the nests, allowing hens to reach and explore each of the nests easily. This access platform is needed to achieve good nest acceptance by the hens and thereby prevent mislaid eggs. In the present experiment, the behavior of hens using 2 different nest access platforms, a plastic grid and 2 wooden perches, was examined. Furthermore, the nests were placed on both sides of the aviary rack (corridor side and outdoor side), either integrated into the aviary rack itself (integrated nest; IN) or placed on the walls of the pens (wall nest; WN), resulting in a 2 × 2 factorial design Four thousand five hundred white laying hens were housed in 20 test pens. The eggs in the nests and mislaid eggs were collected daily, and the behavior of hens on the nest accesses was filmed during wk 25 and 26, using focal observation and scan sampling methods. More balancing, body contact, and agonistic interactions were expected for nests with perches, whereas more walking and nest inspections were expected for nests with grids. There were more mislaid eggs and balancing found in pens equipped with nests with wooden perches. More agonistic interactions and balancing, less standing, and a longer duration of nest inspection were found with the WN compared with the IN. Interactions between platform design and position of the nests were found for duration of nest visits, body contact, and walking, with the highest amount for WN equipped with plastic grids. Nests on the corridor side were favored by the hens. Nest-related behaviors, such as nest inspection, standing, and walking, decreased over time as did the number of hens on the nest accesses, whereas sitting increased. These results indicate that the hens had more difficulties in gripping the perches as designed. The lower number of hens on the nest access platforms in front of IN may be due to a better distribution around nests and tier changes within the aviary rack. Based on these results, grids rather than perches provide for improved nesting behavior.

Influence of front curtain design on nest choice by laying hens.

1. The aim of this study was to investigate the effect of front curtains, one-piece (OP) or sliced in stripes (SL), on the hens' nest preference and laying behaviour in an aviary system. We predicted that hens prefer SL-nests as they could perform nest inspections and enter and leave the nest along its whole width leading to fewer conflicts and more settled laying behaviour. 2. Eight pens containing 20 White Leghorn laying hens were equipped with two roll-away nests, one with OP and one with SL curtains. Laying behaviour was recorded for two days at peak lay in weeks 25 and 26. 3. More nest visits and more nest entries and exits along the whole width of the nest were counted in SL-nests. More sitting events without egg laying were performed in the OP-nests. No differences were found in the number of hens visiting the nests, egg number or aggressive behaviour. 4. Hens appeared to value the seclusion and protection provided by a closed front curtain. However, sliced curtains provided more opportunities to perform nest inspections.

Influence of weaning method on health status and rumen development in dairy calves.

In the artificial rearing of dairy calves, the same feeding plan is applied to all animals during the milk-feeding period, with individual differences attributable to development or health status rarely considered. The aim of this study was 1) to analyze whether the parameters of feeding behavior automatically recorded by a feeding computer and weight gain are suitable for predicting the health status and rumen development of male dairy calves, and 2) to compare a conventional weaning method (end of milk provision at 12 wk of age, n = 23 calves) with a concentrate-dependent weaning method (with reduction in the milk amount depending on the consumption of concentrate, n = 24). The health status of each animal was evaluated daily by a scoring list (health score), and body temperature was measured automatically during each milk intake. In addition, the number of veterinary treatments per calf was recorded. Rumen development was assessed by measuring rumen papillae in 8 rumen areas after slaughter (n = 24, half of each treatment group). During the milk-feeding period, body temperature was elevated (>/=39.5 degrees C) on 40.8 and 43.2% of all days for calves on the concentrate-dependent weaning method and the conventional weaning method, respectively. Hay and concentrate intake (but not milk intake) and weight gain were clearly affected by health status. In addition, health score and the probability of being treated by a veterinarian were significantly related to decreases in concentrate consumption. During the milk-feeding period, increased body temperature, an increased number of veterinary treatments, and decreases in milk consumption were all associated with reduced weight gain. Calves on the concentrate-dependent weaning method were weaned at an average age of 76 d, which was significantly shorter than the age at the end of milk provision for conventionally fed calves (84 d). Weight gain and health status did not differ between treatment groups. Weight gain was positively associated with papillae length. A treatment effect on rumen development could not be found. We conclude that the concentrate-dependent weaning method allows a faster physiological development without any negative impact on rumen development, weight gain, or health status; we therefore recommend its use in practice.

Dominant Negative Mutants of Opaque2 Suppress Transactivation of a 22-kD Zein Promoter by Opaque2 in Maize Endosperm Cells.

In maize endosperm, genes encoding the 22-kD zein class of storage proteins are regulated by the OPAQUE2 locus. The Opaque2 (O2) protein shares homology with the basic domain/leucine zipper class of transcriptional activators. Using microprojectile bombardment, we have shown that O2 is capable of transactivating a 22-kD zein promoter in maize endosperm suspension cultures and in longitudinal sections of intact endosperm. Two mutant forms of the O2 gene were constructed by deleting regions that encode either the basic domain or the first 175 N-terminal residues of the O2 protein. When either of these mutant O2 genes was coexpressed with wild-type O2 in a maize endosperm expression system, O2-mediated transactivation of the 22-kD zein promoter was inhibited specifically and in a dose-dependent manner. Electrophoretic mobility shift assays and immunoprecipitation studies indicated that the mutant O2 proteins form heterodimers with wild-type O2 in vitro. The mutant lacking the basic domain forms heterodimers with wild-type O2, which can no longer bind DNA. In contrast, the product of the N-terminal truncation allele forms homodimers and heterodimers with wild-type O2, both of which can still bind DNA. Because the N-terminal region contains an activation domain, it is likely that these latter complexes are deficient in transactivation. Dominant negative inhibitors of gene expression, such as those constructed here, provide an alternative to antisense RNA approaches for inactivation of gene function in plants.

Kremens v. Bartley: the case for the state.

The authors, co-counsel for the state of Pennsylvania in the child-commitment case to be heard this fall by the Supreme Court, outline the background of the case and present the state's arguments for preserving the rights of parents to commit their children to mental institutions. They warn of the potential psychological harm to both family and child in pitting one against the other in a formal commitment hearing. They also content that the lower-court ruling that granted due-process rights to children causes more problems than it solves. The decision, for example, effectively abolishes the state's program of respite care for mentally retarded youths.

Comparison of ambulance dispatch protocols for nontraumatic abdominal pain.

STUDY OBJECTIVE: To compare rates of undertriage and overtriage of six ambulance dispatch protocols for the presenting complaint of nontraumatic abdominal pain, and to identify the optimal protocol. DESIGN: Retrospective prehospital and emergency department chart review to classify patients' conditions as "emergency" or "nonemergency." Utility analysis was used to identify the preferred protocol and monetary cost-effectiveness analysis to identify the least expensive protocol. SETTING: County emergency medical services (EMS) system with five receiving hospitals serving a mainly urban population of approximately 350,000. PARTICIPANTS: Records of 902 patients who called 911 for nontraumatic abdominal pain were reviewed; patients not transported were excluded. Twenty-seven county EMS medical directors completed questionnaires. RESULTS: Six ambulance dispatch protocols for nontraumatic abdominal pain were developed: indiscriminate-dispatch, four selective protocols, and no-dispatch. A dichotomous classification system was derived prospectively from the prehospital and medical records of patients who had activated the EMS system before the study period to define "emergency" and "nonemergency" conditions associated with nontraumatic abdominal pain. Emergency criteria identified patients with conditions requiring medical treatment within 1 hour. Reviewers determined, for each patient, whether an ambulance would have been dispatched by each of the protocols. Undertriage and overtriage rates were calculated for each protocol. County EMS medical directors assigned utility values to four potential outcomes of ambulance dispatch by the direct scaling method. The outcomes comprised correct and incorrect decisions to dispatch ambulances to patients with and without emergencies. The protocols were compared by decision analysis. A cost analysis was also performed, using an estimated marginal cost per transport of $302. Sensitivity analysis demonstrated the effect of varying the cost of an undertriage error and the cost per response. Of the 788 patients included in the study, 7.8% had conditions defined as emergencies. The four selective ambulance dispatch protocols had overtriage rates ranging from 10% to 51% and undertriage rates of 4% to 7%. None of the protocols was proven superior on the basis of the medical directors' assignment of utility values. The marginal cost of dispatching advanced life support ambulances to all patients with this complaint was $3,838 per emergency. CONCLUSION: The majority of patients with nontraumatic abdominal pain who requested ambulance transport during the study period did not have conditions that were classified as emergencies. In the study model, if an undertriage error costs more than $3,674, indiscriminate ambulance dispatch is the least expensive protocol, and if an undertriage error costs less than $3,674, no ambulance dispatch is the least expensive strategy.

Carisoprodol-induced myoclonic encephalopathy.

CASE REPORT: A 39-year-old man ingested 35 g carisoprodol. He developed agitation, tachycardia, myoclonus, and coma. The blood carisoprodol was 71 micrograms/mL; the meprobamate was 26 micrograms/mL. DISCUSSION: Carisoprodol overdose is thought to induce simple central nervous system depression. This case demonstrates a severe overdose with symptoms more consistent with myoclonic encephalopathy. A review of cases presenting to the San Francisco Division of the California Poison Control System during 1997 suggests that carisoprodol is more commonly associated with agitation and bizarre movement disorders than the current literature suggests. The pharmacology and potential mechanisms of toxicity are discussed. CONCLUSION: Agitation, hypertonia, and a myoclonic encephalopathy may be seen with significant carisoprodol intoxication.

Regulation of anthocyanin biosynthetic genes introduced into intact maize tissues by microprojectiles.

We have employed microprojectiles to deliver genes involved in anthocyanin biosynthesis to cells within intact aleurone and embryo tissues of maize. Clones of the A1 or Bz1 genes were introduced into aleurone tissue that lacked anthocyanins due to mutations of the endogenous A1 or Bz1 gene. Following bombardment, cells within the aleurone developed purple pigmentation, indicating that the mutation in the a1 or bz1 genotypes was corrected by the introduced gene. To analyze the expression of these genes in different genetic backgrounds, chimeric genes containing the 5' and 3' regions of the A1 or Bz1 genes fused to a luciferase coding region were constructed. These constructs were introduced into aleurones of genotypes carrying either dominant or recessive alleles of the C1 and R genes, which are known to regulate anthocyanin production. Levels of luciferase activity in permissive backgrounds (C1, R) were 30- to 200-fold greater than those detected in tissue carrying one or both of the recessive alleles (c1, r) of these genes. These results show that genes delivered to intact tissues by microprojectiles are regulated in a manner similar to the endogenous genes. The transfer of genes directly to intact tissues provides a rapid means for analyzing the genetic and tissue-specific regulation of gene expression.

C1- and R-dependent expression of the maize Bz1 gene requires sequences with homology to mammalian myb and myc binding sites.

Tissue-specific expression of the maize anthocyanin Bronze-1 (Bz1) gene is controlled by the products of several regulatory genes. These include C1 or Pl and R or B that share homology to the myb proto-oncogenes and myc-like genes, respectively. Bz1 expression in embryo tissues is dependent on C1 and an R-sc allele of R. Transient expression from mutated and deleted versions of the Bz1 promoter fused to a luciferase reporter gene was measured in C1, Rscm2 embryos after gene transfer by microprojectiles. This analysis revealed that the sequences between -76 base pairs (bp) and -45 bp and a 9-bp AT-rich block between -88 bp and -80 bp were critical for Bz1 expression. The -76 bp to -45 bp region includes two short sequences that are homologous to the consensus binding sites of the myb- and myc-like proteins. Site-specific mutations of these "myb" and "myc" sequences reduced Bz1 expression to 10% and 1% of normal, respectively. Additionally, a trimer of a 38-bp oligonucleotide containing these myb and myc sites increased the expression of a cauliflower mosaic virus 35S minimal promoter by 26-fold. This enhancement was dependent on both C1 and R. Because the sites critical for Bz1 expression are homologous to the myb and myc consensus binding sequences and the C1 and R proteins share homology with the myb and myc products, respectively, we propose that C1 and R interact with the Bz1 promoter at these sites.

Transactivation of anthocyanin biosynthetic genes following transfer of B regulatory genes into maize tissues.

The C1, B and R genes regulating the maize anthocyanin biosynthetic pathway encode tissue-specific regulatory proteins with similarities to transcriptional activators. The C1 and R regulatory genes are usually responsible for pigmentation of seed tissues, and the B-Peru allele of B, but not the B-I allele, can substitute for R function in the seed. In this study, members of the B family of regulatory genes were delivered to intact maize tissues by high velocity microprojectiles. In colorless r aleurones or embryos, the introduction of the B-Peru genomic clone or the expressed cDNAs of B-Peru or B-I resulted in anthocyanin-producing cells. Luciferase produced from the Bronze1 anthocyanin structural gene promoter was induced 100-fold when co-introduced with the expressed B-Peru or B-I cDNAs. This quantitative transactivation assay demonstrates that the proteins encoded by these two B alleles are equally able to transactivate the Bronze1 promoter. Analogous results were obtained using embryogenic callus cells. These observations suggest that one major contribution towards tissue-specific anthocyanin synthesis controlled by the various alleles of the B and R genes is the differential expression of functionally similar proteins.