Showing papers in "Science in 1957"

Infantile experience and resistance to physiological stress.

Abstract: I t has been reported ( 1 ) that rats which had been \"gentled\" ( that is, picked up and stroked once daily for 21 ,days postweaning) were heavier and reacted Ivith less cardiovascular and gastrointestinal damage under conditions of immobilization for 48 hours than did the \"nongentled\" controls. I n addition, adrenal glands of the nongentled were heavier than those of the gentled animals. Subsequent research ( 2 ) has revealed that rats handled prior to weaning showed .significantly less mortality follo~\\-ing 5 days of total food and water deprivation than did nonhandled rats or rats handled after ~veaning. T h e present experiment (3) was designed to investiqte the response of rats, handled and nonhandled, in infancy (days 1 through 20) to physi.ological stress. T~venty-seven male Sprague DawleyHoltzman albino rats Ivere handled from day 1 through day 20. Handlirlg consisted of removing the pup from the nest, placillg it in a 2.5by 3.5by 6-in. compartment, and then returning it to the nest. This procedure \\\\-as followed oncr daily until weaning, on day 2 1 . Twentynine rats were not handled in any manner through the first 20 days of life and then lvere handled only once, at weanirlg. T h e experimental treatments of handling and nonhandlirlg were randomly assigned to complete litters. ,411 rats within each litter received the same treatment. ,411 animals received no further handling until 70 days of age. At this time 20 rats from the handled group and 20 rats frorn the nonhandled group Ivere given a 20-percent solution of glucosr, injected intraperitoneally at a dosage of 7.5 lnl/100 g of body weight, according to the method described by Brogi ( 4 ) . A 21.4-percent mortality has been reported with this dosagr for normal animals. Following the administration of the glucosr, the animals wrre placed in individi~al cages without food or water. Twrnty-four hours aftcr the glucosr injcction the surviving animals were prrmitted to drink for 1 hour. T h e amount of watrr consurned ivas recorded. They \\\\.ere then uacrificrd. and the left adrrnal was removed and \\\\-eighed. T h e rrmaining ieven handlcd and nine nonhandled rats \\\\-err not e i v ~ n thr glucose injcction but were sacrificed, and the adrenal ~veiglirs \\\\.err determined. T h e mean body \\\\.eight for the groups at \\\\-caning (21 days of age) was 47.74 g for the handled group and 44.31 g for thr nonhandled group. This diffrrrnce \\\\-as significant bryond the 0.05 level. T h r inran weight for thr groups at 70 days was 248.78 g for the handlrd group and 230.28 g for the nonhandled group. This differmcr Ivas significant beyond the 0.01 lrvrl. These rrsults are consistent O NON NON HANDLED HANDLED HANDLED HANDLED GLUCOSE NON GLUCOSE NON INJECTED INJECTED

Image of the Scientist among High-School Students

Abstract: Pneumonia contributes to between 750 000 and 12 million neonatal deaths and an unknown number of stillbirths each year world wide The aetiology depends on time of onset Gram negative bacilli predominate in the first week of life, and Gram positive bacteria after that Streptococcus pneumoniae probably causes about 25% of neonatal pneumonia Interventions that would reduce mortality from this condition would have a large range of beneficial effects: improved maternal health, better management of other common neonatal conditions, and reduced long term childhood and adult morbidity

Mechanisms of Oxygen Metabolism

Abstract: The enzymes which catalyze reactions of molecular oxygen occur in three principle classes: (i) oxygen transferases, (ii) mixed function oxidases, and (iii) electron transferases. The first class catalyzes the transfer of a molecule of molecular oxygen to substrate. The second class catalyzes the transfer of one atom of the oxygen to substrate; the other atom undergoes two-equivalent reduction. The third class catalyses the reduction of molecular oxygen to hydrogen peroxide or to water.

Reductive cleavage of disulfide bridges in ribonuclease.

Abstract: This article was the first of many studies that were generally concerned with the eventual total synthesis of the protein. It contained several original observations that would lead to the conclusion that the refolding of the ribonuclease molecule after full denaturation by reductive cleavage of its four disulfide bonds required that only one of the one hundred five possible pairings of eight sulfhydryl groups to form four disulfide linkages take place.

Leukemia and Ionizing Radiation

Abstract: Quantitative estimates of the genetic effects of ionizing radiation on human beings have been carried out by a number of investigators (1–3). Estimates of this kind involve extrapolating from induced mutation rates in such organisms as Drosophila and mice. Quantitative estimates of the somatic, or “direct,” effects of radiation must also be attempted if the biological hazards of ionizing radiation are to be fully assessed. In the case of direct effects, it is particularly difficult to extrapolate from results with lower organisms, and it becomes important to have data on man himself.

Experiments on Motivation: Studies Combining Psychological, Physiological, and Pharmacological Techniques

Abstract: The importance of motivation in both normal and abnormal behavior is generally recognized. For example, the proper regulation of hunger is vital if the extremes of either malnutrition or obesity are to be a ~ o i d e d ; psycl~otherapists have found that it is much more effective to deal with the underlying motivation in a psycl~ogen

Strontium-calcium movement from soil to man.

Abstract: The calcium reservoirs of the biosphere are becoming labeled to varying degrees with strontium-90 from nuclear weapons. These reservoirs include the human and animal skeleton, the milk, the vegetation, the upper layers of soil, and the waters. The degree of labeling is governed by the dilution that occurs, or the differential behavior of calcium and strontium in various steps of the food chain. This differential behavior normally provides a factor of protection against strontium-90 in the soil and vegetation that may be as high as 25 for the newborn and is most likely not less than 6 for adults, depending on food habits. The physiological steps that are important in the movement of the two elements in the biosphere are described to provide a basis for an approach toward increase of the discrimination against strontium in favor of calcium. Some aspects of agricultural practices are discussed from this standpoint. The matter of hazard from levels now existing and the present need to undertake remedial measures are not discussed, in major part because of lack of experimental data on which to base such considerations.

Swords into Plowshares

Abstract: ByMARKCARO Members ol a student Palestinian group and a campus Jewish group mom nod the victims ol the l ebanon crisis peaceful!) lasi night ai a vigil on ('ollege Hall Green. I ears ol .i clash ai the vigil, which was organii ed h> the Penn Committee lor Palestinian Rights, were alleviated as the program took place peaceful!) on College Hall Green. I he Penn lewish Students' Union had previously stated thai it the committee were to condemn Israel foi last weeks massacre of Palestinian in I ebanon instead ol simply mourning the dead, members would \"reserve the right 10 respond accordingly.\" The committee did condemn Israel, and the union's response was to walk to a nearby area on the green to hold their own vigil. By 8 p.m., the time the vigil was scheduled to begin, a crowd of more than I SO had accumulated in front of the statue of Benjamin Franklin. The crowd included supporters ol the Palestinian group, passers-by, and ,i camera crew from Channel 3 the Channel 6 Actioncam arrived on the scene at 8:10. Union members and other lewish students gathered with In candles around a banner that read: \"Penn Jewish Students Mourn lnnoecnt Deaths.\" The Palestinian group handed out candleto audience members until supplies ran out. The program started around 8:15 with committee member I eslie Gaincs calling lor \"a moment of silence.\" Committee spokesman Paul Robinson then delivered the Palestinian groupstatement . \"We are assembled here to commemorate lasi week'massacre ol Palestinian men. women and children ol Beirut a massacre thai is hut the lastest episode in .1 chain of atrocities, deprivation and genocide committed against the Palesti man people.\" Robinson began, 'Tonight we wani to make n understood that our sorrow and deep angei are noi enough to pre vent a reoccurrence Ol what happened in Beirut last week.\" he continued. \"In these closing decades of the twentieth century, we must make the parties responsible for then actionnamely the Israeli government and then Phalangisi allies.\" ARobinson continued describing the \"displacement'' ol the Palestinians in 1948 and accusing the 'Zionists\" of using \"policies ol state (Continued on page 6) it> MARC Bl \\t sll IN \\ memorandum from School ol Public and 1 i ban Policy \\cting Dean lack Nagel raises furthei ques lions ovei whethet the administra lion properly consulted students and faculty in deciding to phase out the school. I lie Nagel memorandum, an op timisiK description ol Ihe school's recent achievements and the dues lion it was to take m the neat future, idated Scplcinbci 20, foul days before the phase-oul decision i-.i announced It was based on discussions between Nagel and President siuidon Hackney and Provosl i iiom.ii iii hcii eat liet in September. A prominent item in the memorandum, which was addressed |o officers and member directors ol the Samuel S leifund, waa description ol plantot merging SPl P with the City and Regional Planning Department ol the t iraduate School ol I ine \ -. I he new school wai also to assume responsibility tor the undergraduate I i ban Studies program. Questions ovet the naming ol the new school prompted Nagel to check with the president and provosl about the choice Ol names this month Nagel wrote in the memo thai the administrators said they were \"satisfied\" with the name \"School ol Planning and Public Vffairs.\" Nagel said this week he wanot given any indication in his discus sions with the administration thai a decision to close the school was im minent. He said he was informed ol the decision iwo days before it was publish announced Ihe dean'memorandum also discussed the implementation ol the l els Mastet ol Governmental vi ministration program. I he I elM.G.A -in i iculum has been successful m ihe past, And in fluential alumni »i the program are eaget to see ii reinstated at the I Inivet sity I he I eli ellowship I und -up phed $100,000 foi -indent financial aid in 1982 83, which has been divided according to need amoi public policy analysis students in sin p Nagel wrote that some I els money would be allotted to ihe \\l (i v program in Ihe future. Ehrlich said last night ihe ad ministration's decision to phase out SPl P came only several days ' the official announcement last 1 hursday \" \\ final judgmei I made very hortly before the final decision was announced,\" he said Ihe prOVOSl -aid he and the pu-i dent \"talked to a great mans people on campus\" while consid whether 10 eliminate SPl P, and Inlisted the loimei dean. .Kline dean and SIM I' facult) B mdiv idii.ilwho were consulted at least once /< ontinued mi page 7)

Causes and Effects.

Abstract: The study was designed to examine the causes and effects of deforestation. The capacity resource base of forests cannot be under estimated in the economy of Uganda. The study was conducted in three sub-counties of Sironko district that exhibit high incidences of deforestation. The study was guided by two hypotheses: That the demand for forest products, agricultural land and construction materials have no major influence on forests and that there are no important effects of deforestation in Buwalasi, Buteza and Buyobo sub-counties. The study used a descriptive research design with both qualitative and quantitative methods. The samples used in the study consisted of household heads, forest product traders, and district and sub-county key informants. The data was collected using questionnaires, oral interviews, records and observation. The quantitative data was analyzed using Chi square (x2) to test the hypotheses while the qualitative data was analyzed on the basis of content analysis where emerging themes were identified. The empirical data from the secondary sources was analyzed using linear regression. They study inter-alia established that human activities were the most threat to forests. Forests are a national resource base but because they have been depleted have affected the employment and incomes of people at different levels. The following recommendations among others are suggested; Preventive measures guarding against over exploitation and creation of mass awareness on sustainable forest harvesting. Further research on the impact of agro-forestry on sustainable forests’ development is also recommended.