Welch, Sedgwick, and the Hopkins model of hygiene

William H. Welch and William T. Sedgwick, two of the founding fathers of American public health, were both early generation "Hopkins Men." Sedgwick was part of the first group of graduate students to attend Johns Hopkins University, and Welch was part of the initial faculty at the University's medical school. While they never worked together as colleagues at Hopkins, both became interested in the exciting new discoveries of the microbial nature of human disease and developed similar public health programs based on this information. Sedgwick expanded upon these investigations in the new sanitary science program at MIT, where academic public health first emerged in the United States following Sedgwick's appointment in 1883. Welch, who had been exposed to European research in microbiology, promoted microbial research in pathology in Baltimore in 1884. His laboratory-based investigations expanded until they led to the formation of the country's first school of public health in 1916. Thus, a "Hopkins Model" for hygiene and public health emerged from the efforts of both Welch and Sedgwick.     

John Graunt, John Arbuthnott, and the human sex ratio

John Graunt was the first person to compile data that showed an excess of male births over female births. He also noticed spatial and temporal variation in the sex ratio, but the variation in his data is not significant. John Arbuthnott was the first person to demonstrate that the excess of male births is statistically significant. He erroneously concluded that there is less variation in the sex ratio than would occur by chance, and asserted without a basis that the sex ratio would be uniform over all time and space.     

Changes in the yield, and carbohydrate, lipid and protein content of milk during lactation in the rat

The milk yield and composition was studied during the first three lactations of a group of rats. Milk yield increased steadily throughout the three lactations, but was somewhat lower during the first than subsequent lactations. Protein concentration was similar during all three lactations and varied little with stage of lactation. In contrast the lactose concentration, which was reasonably constant for the first 8 days post partum, increased thereafter two-fold by the end of the period studied in all three lactations. However, the N-acetyl-neuraminyl lactose concentration showed somewhat reciprocal changes. Considerable variations in the triacylglycerol concentration was found during the first lactation but few changes were observed during subsequent lactations. The free fatty acid concentration was at all times low and showed no significant changes during or between lactations. At most stages of lactation in raw milk, the major fatty acids are palmitate, oleate and linoleate. However, as lactation progresses there is an increase in the proportion of medium-chain saturated fatty acids and a corresponding decrease in the proportion of long chain unsaturated fatty acids in milk fat. Clearly the composition of milk is not invariable but changes both during and between lactations. Such changes may be expected to have some influence on the metabolism of the offspring.     

Attention, the presolution period, and choice accuracy in pigeons

Six pigeons were trained first on a color then on a form discrimination; four other pigeons were trained first on form and then on color. One of two colors or one of two forms (sample stimuli) appeared in the center of a touch sensitive monitor for 5 pigeons and in the center and in 16 other locations for 5 other pigeons. A peck anywhere within the region in which the sample stimuli appeared produced two white disks (comparison stimuli), one on the left and one on the lower right corners of the screen. Correct left-right choices provided food. Although of no consequence, the location of pecks in presence of the sample was predictive of the pigeon's subsequent choice. Accuracy, choice of the correct comparison stimulus, was greater when the sample stimuli appeared in the center as well as 16 other locations than when it appeared only in the center. The presolution period, the period of chance accuracy prior to evidence of discrimination learning, was decreased on each task following training on the other task. This evidence of facilitation following an extra-dimensional shift was attributed to continued relevance of the conditions under which the first task was learned. The duration of the presolution period was inversely related to asymptotic accuracy-data accounted for by Heinemann's (1983) theory of information processing during the presolution period.     

Temporal relationships among LH, estradiol, and follicle vascularization preceding the first compared with later ovulations during the year in mares

Diameter of the preovulatory follicle, plasma concentrations of LH and estradiol, and vascularization of the follicle wall, based on color-Doppler signals, were characterized in 40 pony mares for 6 days preceding ovulation (Days -6 to -1; preovulatory period). Comparisons between the preovulatory periods preceding the first compared with a later ovulation during the year were used to study the relationships between LH and estradiol and between vascularization and estradiol. Diameter of the preovulatory follicle was greater (P<0.02) and concentration of LH was less (P<0.02) during the first preovulatory period, whereas concentration of estradiol was not different between the first and second preovulatory periods. Vascularized area (cm(2)) of the follicle wall increased at a reduced rate during the first preovulatory period, as indicated by an interaction (P<0.03) between day and group. Vascularized area was similar between the preovulatory groups on Day -6, and a reduced rate of increase resulted in a lesser (P<0.001) area on Day -1 before the first ovulation (1.4+/-0.1cm(2)) than before a later ovulation (2.2+/-0.2 cm(2)). Results demonstrated that follicle vascularization and the LH surge were attenuated preceding the first ovulation of the year with no indication that estradiol was involved in the differences between the first and later ovulations.     

Growth and survival rates of the anadromous trout,Salmo trutta,from the Vardnes River,northern Norway

Synopsis The anadromous brown trout,Salmo trutta L., from the Vardnes River feed in coastal waters during the summer, but spend the winter in freshwater. Mean increase in weight during the sea sojourn ranged from 125 g for first time migrants to 704 g for the largest fish. A loss in weight, increasing with fish size, occurred during the winter residence in freshwater. Growth was positively correlated with the duration of the sea sojourn, which was generally longer in years when higher sea temperatures prevailed. The mean growth rate of the females during the sea sojourn, was generally higher than that of the males. About 37% of first time migrants survived the sea sojourn (mean duration 70 days), compared to 56%–68% of repeat migrants. Minimum estimates of the survival rate in freshwater (duration about 290 days) lay between 66% and 74%. Annual minimum survival was 25% for first time migrants, 37% for second time migrants, and 50% for older fish. The survival rates of the males of both the first- and the second-time migrants were generally higher than those of the respective females. Prolongation of the sea sojourn, due to low water-level in the river at the normal time of ascent, resulted in a further decrease in the survival rate over and above that resulting from the increase in residence time per se.     

Ontogenetic dynamics of the shell convolution diameter of the river snail Viviparus viviparus (Gastropoda, Pectinibranchia, Viviparidae)

The dynamics of the shell convolution diameter with regard to the mollusk age was studied for the river snail Viviparus viviparus. It was found that the diameter of the first (juvenile) convolution remained constant during the ontogenetic development. A weak, but significant increase in the diameter of the second and the third shell convolutions (also juvenile) was observed during the first year of postembryonic development. The forth and the fifth shell convolutions were formed during the first year of mollusk life after hatching; their diameters increased gradually during the second year, and remained constant for the remainder of the life span.     

Baculoviruses and apoptosis: the good, the bad, and the ugly

Since 1991, when a baculovirus was first shown to inhibit apoptosis of its host insect cells, considerable contributions to our knowledge of apoptosis have arisen from the study of these viruses and the anti-apoptotic genes they encode. Baculovirus anti-apoptotic genes include p35, which encodes the most broadly acting caspase inhibitor protein known, and iap (inhibitor of apoptosis) genes, which were the first members of an evolutionarily conserved gene family involved in regulation of apoptosis and cytokinesis in organisms ranging from yeast to humans. Baculoviruses also provide an ideal system to study the effects of an apoptotic response on viral pathogenesis in an animal host. In this review, I discuss a number of interesting recent developments in the areas of apoptotic regulation by baculoviruses and the effects of apoptosis on baculovirus replication and pathogenesis.     

Seasonal and age changes in the thymus gland of the Red fox, Vulpes vulpes,

Seasonal and age changes in thymus weight and histological structure were examined in the Red fox ( Vulpes vulpes ). Growth in the fox thymus slowed down after birth compared with the last third of foetal existence, but the gland still grew rapidly to reach a peak first year weight when the cubs were 20 weeks of age. From this point the thymus in both sexes decreased markedly in weight to reach a low point by the beginning of the first breeding season. During this involution lobule structure broke down and adipose tissue and connective tissue was laid down in the gland. Recovery of the thymus towards the second year weight maximum was accompanied by the regaining of lobule structure and the gland resembled that of the juvenile again. The male thymus increased in weight from the middle of the mating season, but recovery in the female thymus was delayed until the end of lactation. Involution occurred prior to the second breeding season. Thereafter, the gland never attained the high weights seen in the first two years of life, but histological changes still occurred even in old animals. The thymus gland of animals infected with sarcoptic mange is described.     

On the early growth of 0+ perch, Perca fluviatilis, in Windermere

SUMMARY. The growth in length and weight (wet and dry) of 0+ perch Perca fluviatilis during their first summer of life in Windermere, has been investigated. Two major stanzas, occurring during and after metamorphosis, characterize the growth of 0+ perch in Windermere. The change from one stanza to another takes place between six and eight weeks after hatching. The exponential rate of growth in length was 0.26 and 0.27 mm mm⁻¹ week⁻¹ for the first stanzas of 1975 and 1976, respectively, and decreased to about 0.08 and 0.07 mm mm⁻¹ week⁻¹ for the second stanzas of the same years. Similarly, the growth in both wet and dry weights decreased from the first to the second stanza. Growth of 0+ perch was found to be logistic, and could not be described by the von Bertalanffy growth curve. The relationship between weight and length was allometric and the power values for length were, for wet weight: 4.154 (in 1975) and 4.033 (in 1976) for the first stanza and 2.400 (in 1975) and 2.734 (in 1976) for the second stanza; for dry weight: 3.988 (1975) and 3.971 (1976) for the first stanza and 3.066 (1975) and 2.651 (1976) for the second stanza. Half of the total growth was completed in 47% (1975) and 40% (1976) of the total growth period to the end of the summer.     

Determination of growth and maturation in the common frog, Rana temporaria, by skeletochronology

Growth and maturation in a Swiss population of Rana temporaria were studied in 1983 and 1984 by means of skeletochronology. Resting line (growth ring) diameters were used to back-calculate individual body sizes in previous years; these permitted establishment of an average growth curve and determination of individual ages and sizes at first reproduction. Growth was rapid up to maturation, but continued thereafter at a decreased rate. Males were larger than females at age two but females grew faster thereafter, causing sexual dimorphism in adult body sizes. Body size distributions for both years and for frogs recaptured and first captured in 1984 were established. Growth in immatures was positively, but in adults negatively correlated with body size, with considerable variation at all sizes. Individual adult sizes were positively correlated with body sizes at the end of the first year. Average individual age at first reproduction was 2.8 years in males and 3.1 years in females (range in both sexes two to four years). There is no evidence for a two-year-cycle of reproduction.     

Crystallography, evolution, and the structure of viruses

My undergraduate education in mathematics and physics was a good grounding for graduate studies in crystallographic studies of small organic molecules. As a postdoctoral fellow in Minnesota, I learned how to program an early electronic computer for crystallographic calculations. I then joined Max Perutz, excited to use my skills in the determination of the first protein structures. The results were even more fascinating than the development of techniques and provided inspiration for starting my own laboratory at Purdue University. My first studies on dehydrogenases established the conservation of nucleotide-binding structures. Having thus established myself as an independent scientist, I could start on my most cherished ambition of studying the structure of viruses. About a decade later, my laboratory had produced the structure of a small RNA plant virus and then, in another six years, the first structure of a human common cold virus. Many more virus structures followed, but soon it became essential to supplement crystallography with electron microscopy to investigate viral assembly, viral infection of cells, and neutralization of viruses by antibodies. A major guide in all these studies was the discovery of evolution at the molecular level. The conservation of three-dimensional structure has been a recurring theme, from my experiences with Max Perutz in the study of hemoglobin to the recognition of the conserved nucleotide-binding fold and to the recognition of the jelly roll fold in the capsid protein of a large variety of viruses.     

Effects of aging and dietary restriction on ubiquitination, sumoylation, and the proteasome in the spleen

In the present study, we demonstrate for the first time that aging increases the levels of ubiquitinated protein in the spleen, and that dietary restriction (DR) significantly reduces these age-related increases in ubiquitinated protein. Sumoylated protein, proteasome subunits, and a protein essential for proteasome biogenesis (POMP1) were also increased with age in the spleen but were not significantly affected by DR. Chymotrypsin-like proteasome activity was elevated in the aged spleen, and was not significantly altered by DR. Together, these data demonstrate for the first time the multiple effects of aging and DR on ubiquitination, sumoylation, and the proteasome in the spleen.     

Expression of the autofluorescent protein, DsRed2, in the recombinants of the ectomycorrhizal basidiomycete, Suillus grevillei, generated by Agrobacterium-mediated transformation

Recombinants were generated from the ectomycorrhizal basidiomycete, Suillus grevillei, through agroinfection using a binary vector carrying the hygromycin B resistance and the autofluorescent protein, DsRed2, markers. DsRed2 was driven by a cis-regulatory region of the glyceraldeyde-3-phosphate dehydrogenase gene (gpd) from the wood-rotting basidiomycete, Coriolus hirsutus, which contains promoters and 5′ gpd sequences with first through fourth exons and expressed for the first time in Suillus spp. The transformation system and recombinants expressing an autofluorescent protein may be useful in genetic analysis of the symbiosis.     

Co-expression of the Plasmodium falciparum molecular chaperone, PfHsp70, improves the heterologous production of the antimalarial drug target GTP cyclohydrolase I, PfGCHI

Molecular chaperones have been used for the improved expression of target proteins within heterologous systems; however, the chaperone and target protein have seldom been matched in terms of origin. We have developed a heterologous co-expression system that allows independent expression of the plasmodial chaperone, PfHsp70, and a plasmodial target protein. In this study, the target was Plasmodium falciparum GTP cyclohydrolase I (PfGCHI), the first enzyme in the plasmodial folate pathway. The sequential expression of the molecular chaperone followed by the target protein increased the expression of soluble functional PfGCHI. His-tagged PfGCHI was successfully purified using nickel affinity chromatography, and the specific activity was determined by high performance liquid chromatography with spectrofluorometeric detection to be 5.93nmol/h/mg. This is the first report of a heterologous co-expression system in which a plasmodial chaperone is harnessed for the improved production and purification of a plasmodial target protein.     

Reproduction in dairy cattle: Effect of age,cow condition,production level,calving-to-first-service interval and the ‘male’

A study was conducted to determine the effect of various factors on the reproductive performance of approximately 1700 cows in 12 seasonally calving dairy herds in North Western Tasmania. Submission rate (percent of cows submitted for service for the first time in the first 24 days of the mating season) rose from 60% to 97% as cow condition score improved from 3 to 5.5. There was no effect on non-return rates (percent of cows submitted for service for the first time in the first 24 days of mating which did not return to service in the subsequent 21 days), provided condition score was 3.5 or over. Milk fat yield was positively correlated to both submission and non-return rate until milk fat yield exceeded 1.0 kg/day when both fell (from 79% to 71% and from 73% to 38%, respectively). Non-return rate was 46% when the calving-to-first-service interval was less than 40 days after which it rose to a more normal 65%. Submission rates were unaffected by calving-to-first-service interval. There was a significant positive correlation between age and non-return rate, but not between age and submission rate, although submission rate also tended to be higher in older cattle. The proportion of cows having short cycles (less than 18 days) was 18%. In contrast to reports in other species, the presence of the male did not improve oestrous detection or non-return rate of cows in the immediate post-partum period.     

铁杉球蚜的生物学及空间分布

通过对铁杉(Tusga chinensis Pritz)-云杉(Picea retroflexac Mast)、铁杉-华山松(Pinus armardi Franch)、云南铁杉(Tusga domosa Eichler)-槭树(Acer mono Maxim)-桦木(Betula platyphylla Suk)四川主要铁杉林类型中铁杉球蚜Adelges tsugae Annand林间定株、种群随机抽样、室内饲养研究表明,铁杉球蚜在四川1年发生2代(越冬代和第1代),世代重叠,成虫营孤雌生殖。越冬代从4月上旬至第2年的4月下旬,产卵盛期在5月下旬,平均产卵量为15.58粒,1龄若虫具有滞育越夏习性;第1代从12月下旬至8月中旬,产卵盛期在3月下旬,平均产卵量为67.37粒,并可产生有翅成虫,但无转主危害现象。种群的发育与温度有相关性,温度高林分种群发育进度快于温度低林分。该虫的危害与生境有一定相关性,铁杉针阔混交林危害重于铁杉针叶林;同一树冠不同层次之间、不同方位之间危害程度差异不显著;当年受害严重的树株第2年受害不严重。     

Testosterone,oxytocin, and the development of human parental care

The steroid testosterone (T) and neuropeptide oxytocin (OT) have each been implicated in the development of parental care in humans and animals, yet very little research addressed the interaction between these hormones at the transition to parenthood in mothers and fathers. One hundred and sixty mothers and fathers (80 couples) were visited 1 and 6 months after the birth of their first child, plasma OT and T were assayed at each time-point, and interactions between each parent and the infant were observed and micro-coded for two key parental behaviors; affectionate touch and parent-infant synchrony. T showed gender-specific effects. While paternal T was individually stable across the first six months of parenting and predicted lower father-infant synchrony, maternal T was neither stable nor predictive of maternal behavior. An interaction of OT and T showed that T has complex modulatory effects on the relations of OT and parenting. Slope analysis revealed that among fathers, only when T was high (+ 1SD), negative associations emerged between OT and father affectionate touch. In contrast, among mothers, the context of high T was related to a positive association between OT and maternal touch. Our findings, the first to test the interaction of OT and T in relation to observed maternal behavior, underscore the need for much further research on the complex bidirectional effects of steroid and neuropeptide systems on human mothering and fathering.     

Report of the 14th Genomic Standards Consortium Meeting,Oxford, UK,September 17-21, 2012.

This report summarizes the proceedings of the 14^th workshop of the Genomic Standards Consortium (GSC) held at the University of Oxford in September 2012. The primary goal of the workshop was to work towards the launch of the Genomic Observatories (GOs) Network under the GSC. For the first time, it brought together potential GOs sites, GSC members, and a range of interested partner organizations. It thus represented the first meeting of the GOs Network (GOs1). Key outcomes include the formation of a core group of “champions” ready to take the GOs Network forward, as well as the formation of working groups. The workshop also served as the first meeting of a wide range of participants in the Ocean Sampling Day (OSD) initiative, a first GOs action. Three projects with complementary interests – COST Action ES1103, MG4U and Micro B3 – organized joint sessions at the workshop. A two-day GSC Hackathon followed the main three days of meetings.