Heat stress of gilts around farrowing causes oxygen insufficiency in the umbilical cord and reduces piglet survival.

Late gestating sows are susceptible to high ambient temperatures, possibly causing farrowing complications and reducing piglet survival. This experiment aimed to quantify in the days leading up to farrowing the impact of sow heat stress (HS) on farrowing physiology and survival of the piglets. Pregnant primiparous sows (gilts) were allocated to either thermoneutral control (CON, n = 8; constant 20 °C) or cyclical HS conditions (n = 8; 0900 h to 1700 h, 30 °C; 1700 h to 0900 h, 28 °C) from d 110 of gestation until farrowing completion. Gilt respiration rate, skin temperature and rectal temperature were recorded daily, and farrowing duration was quantified by video analyses. Blood samples were collected from the piglet umbilical vein at birth. At 48 h of age, piglet growth was quantified by morphometric analyses. The thermal exposure model induced HS and respiratory alkalosis in the gilts, as indicated by increased respiration rate, rectal temperature, skin temperature (all P < 0.001), plasma cortisol (P = 0.01) and blood pH (P < 0.001). Heat-stressed gilts took longer to start expelling placentae (P = 0.003), although the active farrowing duration was not significantly different between treatments. Stillbirth rates were higher in the HS group (P < 0.001), with surviving piglets at birth having lower umbilical vein partial pressure of oxygen (P = 0.04), oxygen saturation rate (P = 0.03) and tending to have increased lactate concentrations (P = 0.07). At birth, piglet skin meconium staining scores were greater in the HS group (P = 0.022). At 48 h of age, piglets from the HS group had reduced small intestinal length (P = 0.02), reduced jejunal crypt depth (P = 0.02) and lighter absolute brain weight (P = 0.001). In contrast, piglet BW, growth rate, relative organ weight and small intestinal mucosal barrier function did not change between treatments. Collectively, these findings demonstrated gilt HS during late gestation caused farrowing complications and reduced the umbilical oxygen supply to the piglets at parturition, leading to increased risks of piglet stillbirth with implications on impaired neonatal survivability and development.

Mixed-methods process evaluation of a residence-based SARS-CoV-2 testing participation pilot on a UK university campus during the COVID-19 pandemic.

BACKGROUND: Regular testing for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is an important strategy for controlling virus outbreaks on university campuses during the COVID-19 pandemic but testing participation rates can be low. The Residence-Based Testing Participation Pilot (RB-TPP) was a novel intervention implemented at two student residences on a large UK university campus over 4 weeks. The aim of the pilot was to increase the frequency of asymptomatic SARS-CoV-2 saliva testing onsite. This process evaluation aimed to determine whether RB-TPP was implemented as planned and identify implementation barriers and facilitators. METHODS: A mixed-methods process evaluation was conducted alongside the RB-TPP. Evaluation participants were students (opting in, or out of RB-TPP) and staff with a role in service provision or student support. Monitoring data were collected from the intervention delivery team and meeting records. Data were collected from students via online survey (n = 152) and seven focus groups (n = 30), and from staff via individual interviews (n = 13). Quantitative data were analysed descriptively and qualitative data thematically. Barriers and facilitators to implementation were mapped to the 'Capability, Opportunity, Motivation-Behaviour' (COM-B) behaviour change framework. RESULTS: Four hundred sixty-four students opted to participate in RB-TPP (98% of students living onsite). RB-TPP was implemented broadly as planned but relaxed social distancing was terminated early due to concerns relating to national escalation of the COVID-19 Delta variant, albeit testing continued. Most students (97.9%) perceived the period of relaxed social distancing within residences positively. The majority engaged in asymptomatic testing (88%); 46% (52% of testers) were fully compliant with pre-determined testing frequency. Implementation was facilitated by convenience and efficiency of testing, and reduction in the negative impacts of isolation through opportunities for students to socialise. Main barriers to implementation were perceived mixed-messages about the rules, ambivalent attitudes, and lack of adherence to COVID-19 protective measures in the minority. CONCLUSIONS: This process evaluation identifies factors that help or hinder the success of university residence-based outbreak prevention and management strategies. RB-TPP led to increased rates of SARS-CoV-2 testing participation among students in university residences. Perceived normalisation of university life significantly enhanced student mental wellbeing. The complexity and challenge generated by multiple lines of communication and rapid adaptions to a changing pandemic context was evident. TRIAL REGISTRATION NUMBER: UKAS 307727-02-01; Pre-results. CLINICALTRIALS: gov Identifier: NCT05045989 ; post-results (first posted, 16/09/21). ETHICAL APPROVAL: Faculty of Medicine & Health Sciences Research Ethics Committee, University of Nottingham (Ref: FMHS 96-0920).

A qualitative exploration of the psychological impacts of living with the uncertainty of persistent flood risk.

OBJECTIVES: Flooding is associated with increased psychological morbidity; however, the impact of living with the uncertainty of flood risk has not been explored. The aim of this study was to generate insight into individual experiences of living with persistent flood risk, how it affects psychological well-being, and the forms of support deemed appropriate to mitigate psychological risks. STUDY DESIGN: A qualitative study was conducted using semistructured interviews with participants who lived in a persistent flood risk area in Nottinghamshire, UK. METHODS: 40 participants were interviewed. The study adopted an interpretivist constructionist position, and the transcripts were analysed using inductive thematic analysis. RESULTS: Persistent flood risk was seen as a significant stressor, regardless of previous flood history. Some participants reported anxiety in anticipation of a future flood event and demonstrated low self-efficacy, with subsequent feelings of helplessness in responding to flood risk. Individuals who lacked acceptance of flood risk displayed higher anxiety and lower resilience. Recognition of flood risk as a psychological stressor was requested in future support. CONCLUSIONS: Living with the uncertainty of persistent flood risk can have significant psychological impacts. Interventions that facilitate the empowerment of individuals living with persistent flood risk may strengthen psychological resilience.

Heterogeneity of enterochromaffin cells within the gastrointestinal tract.

Enterochromaffin cells were the first endocrine cells of the gastrointestinal tract to be chemically distinguished, almost 150 years ago. It is now known that the chromaffin reaction of these cells was due to their content of the reactive aromatic amine, 5-hydroxytryptamine (5-HT, also known as serotonin). They have commonly been thought to be a special class of gut endocrine cells (enteroendocrine cells) that are distinct from the enteroendocrine cells that contain peptide hormones. The study by Martin et al. in the current issue of this journal reveals that the patterns of expression of nutrient receptors and transporters differ considerably between chromaffin cells of the mouse duodenum and colon. However, even within regions, chromaffin cells differ; in the duodenum there are chromaffin cells that contain both secretin and 5-HT, cholecystokinin and 5-HT, and all three of secretin, cholecystokinin, and 5-HT. Moreover, the ratios of these different cell types differ substantially between species. And, in terms of function, 5-HT has many roles, including in appetite, motility, fluid secretion, release of digestive enzymes and bone metabolism. The paper thus emphasizes the need to define the many different classes of enterochromaffin cells and relate this to their roles.

Cat striate cortex: monocular and interocular comparisons of spatial-frequency selectivity.

Spatial frequency and bandwidth characteristics were determined for neurones in cat striate cortex. Responses to drifting sine-wave gratings, optimized for orientation, direction and velocity, were determined over a range of spatial frequencies. Comparative measurements of spatial frequency tuning at constant velocity and at constant temporal drift frequency revealed that, overall, tuning derived by either method was similar. Results were evaluated in relation to neuronal class (simple or complex); complex cell subclass (standard, intermediate or special), defined by length summation; directionality; and velocity selectivity. Distributions of optimal spatial frequency for simple and complex neurones were comparable. By contrast, bandwidths of simple neurones were markedly narrower than for complex neurones. Standard complex neurones, in turn, had narrower bandwidths than special or intermediate complex neurones. Optimal spatial frequency correlated inversely with optimal velocity, directly with orientation selectivity. Thus, neurones tuned to high spatial frequencies tended to respond optimally to low velocities, and were more sharply orientation selective, than neurones tuned to low spatial frequencies. In binocular neurones, spatial frequency tuning characteristics of the two monocular inputs were compared. For either eye, spatial frequency tuning curves were reproducible over time. In a minority of neurones, spatial frequency characteristics were matched for the two eyes. A majority showed mismatch in spatial frequency characteristics between the eyes. Individual neurones were tuned to different bands of spatial frequencies through either eye; more sharply spatial-frequency selective through one eye than the other; or had both dissimilar bandwidth and spatial frequency. Changing input spatial-frequency resulted in profound, systematic shifts in ocular dominance. These were progressive in the case of spatial-frequency mismatch. In cases of bandwidth, or bandwidth and spatial-frequency mismatch, the eye associated with more sharply-tuned input exerted relatively greater influence at centre frequencies, the other eye relatively greater influence at extreme frequencies. There was a marginal tendency for the dominant (or contralateral) eye to be tuned to higher spatial frequencies than the more weakly driving (or ipsilateral) eye. By contrast, interocular differences in bandwidth were pronounced: in a majority of neurones the dominant eye was more broadly tuned than the more weakly driving eye. Related to the established preponderance of contralaterally dominated cortical neurones, the input from the contralateral eye was markedly more broadly tuned than that from the ipsilateral eye, consistent with the notion that stronger drive is associated with greater pooling of inputs. These differences have important implications for binocular vision and, potentially, for coding of visual perspective.

Quantification of excitatory receptive fields of complex neurones in cat striate cortex.

Excitatory receptive field (ERF) response profiles and length summation functions were derived from complex neurones in cat striate cortex. Measured length summation was compared with summation predicted from integration over ERF profiles. In a minority of neurones, measured and predicted summation were well matched. In the majority, whether end-stopped or not, responsiveness in length summation tests was appreciably greater than predicted for short stimuli, compared with ERF profiles. The mismatch was least in standard and greatest in special complex neurones; in the latter group, response levels to long stimuli fell well below predicted levels. In end-stopped neurones the decremental portion of length summation functions was not predicted by ERF profiles. These results implicate the involvement of non-linear mechanisms, whereby concomitant stimulation of central regions of the receptive field (RF) potentiate the efficacy of loci towards either end of the RF.

Muscle and liver pyruvate kinases are closely related: amino acid sequence comparisons.

Previous evidence has shown that the M1 and L pyruvate kinase isozymes differ markedly in kinetic and immunological properties, amino acid compositions and peptide maps. However, the amino acid sequence results we present here for the N-terminal region and for a region of the C domain show that the M1 and L isozymes are very similar. The variable length of the N-terminal sequences also explains the difference in regulation by phosphorylation between the M1 and L isozymes. The M1 isozyme lacks the serine residue that has been shown to be phosphorylated in the L isozyme.

Human skeletal-muscle aldolase: N-terminal sequence analysis of CNBr- and o-iodosobenzoic acid-cleavage fragments.

Fructose-1,6-bisphosphate aldolase was purified from human skeletal-muscle by affinity elution chromatography. Four CNBr-cleavage fragments were purified by gel filtration, and their N-terminal amino acid sequences were determined. Cleavage with o-iodosobenzoic acid at the three tryptophan residues also yielded fragments suitable for N-terminal sequence analysis. Thus, the sequence of 272 of the 363 residues was established. These sequence results allow many of the discrepancies between the two published rabbit skeletal-muscle aldolase sequences to be resolved. The human aldolase sequence reported here is 96% identical to a "consensus" rabbit aldolase sequence. A comparison with a partial sequence of Drosophila aldolase (103 residues) shows 80% identity. The determination of the amino acid sequence of human aldolase is important for the interpretation of the crystal structure of this enzyme.

A comparison of the structure and activity of cat and trout muscle pyruvate kinases.

Pyruvate kinase was purified from cat and trout muscle. The enzymes had similar amino acid compositions and subunit molecular weights. In contrast to the mammalian enzyme, the trout muscle pyruvate kinase was activated by fructose 1,6-bisphosphate. However, unlike the L-type pyruvate kinase from mammalian liver it was not phosphorylated by cyclic-AMP-dependent protein kinase. The purified enzyme from cat muscle was carboxymethylated with iodo[2-14C]acetic acid under conditions that led to the preferential labelling of one especially reactive thiol group. The labelled enzyme was cleaved with CNBr, and the radioactive fragment purified. Amino acid sequence analysis of the reactive-thiol-containing fragment from cat muscle pyruvate kinase showed it had the following sequence: Ile-Gly-Arg-[14C]CmCys-Asn-Arg-Ala-Gly-Lys-Pro-Val-Ile-CmCys-Ala-Thr-Gln- Hse. The corresponding peptide from trout pyruvate kinase had only one difference in its amino acid composition and the sequence around the reactive thiol was identical.

The complete amino acid sequence of yeast phosphoglycerate kinase.

The complete amino acid sequence of yeast phosphoglycerate kinase, comprising 415 residues, was determined. The sequence of residues 1-173 was deduced mainly from nucleotide sequence analysis of a series of overlapping fragments derived from the relevant portion of a 2.95-kilobase endonuclease-HindIII-digest fragment containing the yeast phosphoglycerate kinase gene. The sequence of residues 174-415 was deduced mainly from amino acid sequence analysis of three CNBr-cleavage fragments, and from peptides derived from these fragments after digestion by a number of proteolytic enzymes. Cleavage at the two tryptophan residues with o-iodosobenzoic acid was also used to isolate fragments suitable for amino acid sequence analysis. Determination of the complete sequence now allows a detailed interpretation of the existing high-resolution X-ray-crystallographic structure. The sequence -Ile-Ile-Gly-Gly-Gly- occurs twice in distant parts of the linear sequence (residues 232-236 and 367-371). Both these regions contribute to the nucleoside phosphate-binding site. A comparison of the sequence of yeast phosphoglycerate kinase reported here with the sequences of phosphoglycerate kinase from horse muscle and human erythrocytes shows that the yeast enzyme is 64% identical with the mammalian enzymes. The yeast has strikingly fewer methionine, cysteine and tryptophan residues.

The complete amino acid sequence of human erythrocyte diphosphoglycerate mutase.

The complete amino acid sequence of human erythrocyte diphosphoglycerate mutase, comprising 239 residues, was determined. The sequence was deduced from the four cyanogen bromide fragments, and from the peptides derived from these fragments after digestion with a number of proteolytic enzymes. Comparison of this sequence with that of the yeast glycolytic enzyme, phosphoglycerate mutase, shows that these enzymes are 47% identical. Most, but not all, of the residues implicated as being important for the activity of the glycolytic mutase are conserved in the erythrocyte diphosphoglycerate mutase.

Conservation of high efficiency promoter sequences in Saccharomyces cerevisiae.

The position of the yeast phosphoglycerate kinase (PGK) gene has been mapped on a 2.95kb Hind III fragment. We have determined the nucleotide sequence of the 5' flanking region and compared this sequence with those from 16 other yeast genes. PGK, like all other yeast genes has an adenine residue at position -3. It has two possible TATA boxes at positions -114 and -152 and a CAAT box at -129. In addition we have defined a structure at position -63 to -39 that is common to all yeast genes that encode an abundant RNA. This structure is a CT-rich block followed, about 10 nucleotides later, by the sequence CAAG.

The amino acid sequence of yeast phosphoglycerate mutase.

The complete amino acid sequence of yeast phosphoglycerate mutase comprising 241 residues has been determined. The sequence was deduced from the two cyanogen bromide fragments, and from the peptides derived from these fragments after digestion by a number of proteolytic enzymes. Determination of this sequence now allows a detailed interpretation of the existing high-resolution X-ray crystallographic structure. A comparison of the sequence reported here with the sequences of peptides from phosphoglycerate mutases from other species, and with the sequence of erythrocyte diphosphoglycerate mutase, indicates that these enzymes have a high degree of structural homology. Autolysis of phosphoglycerate mutase by yeast extracts leads to the complete loss of mutase activity, and the formation of electrophoretically distinguishable forms (R. Sasaki, E. Sugimoto & H. Chiba, Archs Biochem. Biophys. 115, 53-61 (1966)). It is apparent from the amino acid sequence that these changes are due to the loss of an 8-12 residue peptide from the C-terminus.

Sequence and structure of yeast phosphoglycerate kinase.

The structure of yeast phosphoglycerate kinase has been determined with data obtained from amino acid sequence, nucleotide sequence, and X-ray crystallographic studies. The substrate binding sites, as deduced from electron density maps, are compatible with known substrate specificity and the stereochemical requirements for the enzymic reaction. A carboxyl-imidazole interaction appears to be involved in controlling the transition between the open and closed forms of the enzyme.

Structure and activity of phosphoglycerate mutase.

The structure of yeast phosphoglycerate mutase determined by X-ray crystallographic and amino acid sequence studies has been interpreted in terms of the chemical, kinetic and mechanistic observations made on this enzyme. There are two histidine residues at the active site, with imidazole groups almost parallel to each other and approximately 0.4 nm apart, positioned close to the 2 and 3 positions of the substrate. The simplest interpretation of the available information suggests that a ping-pong type mechanism operates in which at least one of these histidine residues participates in the phosphoryl transfer reaction. The flexible C-terminal region also plays an important role in the enzymic reaction.

The complete amino-acid sequence of hen ovalbumin.

The complete amino acid sequence of hen ovalbumin, comprising 385 residues, has been determined. The sequence was deduced from the 17 cyanogen bromide fragments and from peptides derived by digestion with a number of proteolytic enzymes. The molecular weight of the polypeptide chain of ovalbumin is 42699. Ovalbumin has four sites of postsynthetic modification; in addition to the acetylated N terminus, the carbohydrate moiety is located at Asn-292, and the two phosphorylated serines are at residues 68 and 344. The 'signal sequence' of ovalbumin is between residues 234 and 252. The heptapeptide released during the conversion of ovalbumin to plakalbumin by subtilisin digestion corresponds to residues 346-352. The hen ovalbumin polymorphism characterised by an Asn leads to Asp replacement results from a mutation at residue 311. The amino acid sequence of ovalbumin deduced from these amino acid sequence studies is in complete agreement with the sequence of mRNA determined by McReynolds et al. [Nature (Lond.) 273, 723-728 (1978)].

Sequences of sixteen phosphoserine peptides from ovalbumins of eight species.

Phosphoserine peptides have been isolated by a diagonal electrophoresis method from proteolytic digests of ovalbumins from hen, grouse, turkey, golden pheasant, magpie goose, chinese goose, Aylesbury duck and fulvous whistling duck. The amino acid sequences of these peptides have been determined. There are two sites of phosphorylation in each ovalbumin, which are located in two different regions of the ovalbumin molecule. Amino acid replacements are more frequent in the site 1 sequences than in the site 2 sequences. Both site 1 and site 2 sequences contain invariant residues. Sequence variations occur near the serine residues that are phosphorylated, but the amino acid two residues C-terminal to the phosphoserine is always glutamic acid, suggesting that this may be a recognition signal for the phosphorylating enzyme. Variations in amino acid sequence among the species are consistent with differences in the ovalbumins determined by peptide mapping and quantitative immunoprecipitation assays. A phylogenetic tree has been constructed from a comparison of the sequences of 248 residues from the eight ovalbumins.