Ecological drivers of helminth infection patterns in the Virunga Massif mountain gorilla population.

The Virunga Massif mountain gorilla population has been periodically monitored since the early 1970s, with gradually increasing effort. The population declined drastically in the 1970s, but the numbers stabilized in the 1980s. Since then, the population has been steadily increasing within their limited habitat fragment that is surrounded by a dense human population. We examined fecal samples collected during the Virunga 2015-2016 surveys in monitored and unmonitored gorilla groups and quantified strongylid and tapeworm infections using egg counts per gram to determine environmental and host factors that shape these helminth infections. We showed that higher strongylid infections were present in gorilla groups with smaller size of the 500-m buffered minimum-convex polygon (MCP) of detected nest sites per gorilla group, but in higher gorilla densities and inhabiting vegetation types occurring at higher elevations with higher precipitation and lower temperatures. On the contrary, the impact of monitoring (habituation) was minor, detected in tapeworms and only when in the interaction with environmental variables and MCP area. Our results suggest that the Virunga mountain gorilla population may be partially regulated by strongylid nematodes at higher gorilla densities. New health challenges are probably emerging among mountain gorillas because of the success of conservation efforts, as manifested by significant increases in gorilla numbers in recent decades, but few possibilities for the population expansion due to limited amounts of habitat.

A prospective trial of the effects of isotretinoin on quality of life and depressive symptoms.

BACKGROUND: Isotretinoin is an efficacious treatment for acne, but has been controversially linked with depression. OBJECTIVES: This study aimed to examine the effects of isotretinoin on quality of life(QoL) and depression using a prospective design. METHODS: The WHOQOL-BREF QoL measure and Centre for Epidemiological Studies Depression Scale were administered to consecutive outpatients with acne who were prescribed either isotretinoin (n = 65) or antibiotic treatment (n = 31).Patients and physicians rated acne severity independently. Groups were compared at baseline with a matched community sample (n = 94) and measurements repeated at 3 months for treatment groups. RESULTS: There were no differences between the three groups at baseline in terms of age, gender, depression or overall QoL. Acne was more severe in the treatment groups (P < 0·001). Depression was negatively correlated with QoL (P < 0·001)and hence was included as a covariate in repeated-measures analyses of QoL.Acne improved over time in both treatment groups (F = 48·2, P < 0·001). There was no detectable deterioration in depression score in either group (F = 1·1, not significant). QoL in the physical and social domains improved (P < 0·001) while psychological and environmental QoL was unchanged over time. The improvement in social QoL was greater in the isotretinoin group (P < 0·05). Those patients with higher baseline depression scores showed greater improvements in physical, psychological and social QoL (P < 0·001). CONCLUSIONS: Treatment of acne improves QoL, particularly in those with more depressive symptoms at the outset. Mood deterioration was not detected, but the possibility of subtle or rare mood effects of isotretinoin cannot be ruled out.

Does topical tacrolimus induce lentigines in children with atopic dermatitis? A report of three cases.

Three children with severe atopic dermatitis were noted at routine follow-up to have developed multiple small pigmented macules during long-term therapy with topical tacrolimus 0.1% (Protopic, Fujisawa). Representative lesions in two of the three cases were confirmed histologically as simple lentigines. The focal distribution of lentigines to sites of tacrolimus use, and the temporal association between use of tacrolimus and development of lesions, suggest that topical tacrolimus is of direct aetiological relevance to their development. Careful long-term follow-up will be required to assess the clinical implications of these findings and whether they represent an increase in risk for melanocytic neoplasia.

An electret passive environmental 222Rn monitor based on ionization measurement.

The electret passive environmental 222Rn monitor (E-PERM) is an extension of electret dosimeters used for measurement of x and gamma radiation. An E-PERM consists of a small cup or canister, having an electret at the bottom, and a filtered inlet at the top. The 222Rn gas entering through the filter and the decay products formed inside the cup generate ions which are collected by the electret. The reduction of charge (or surface potential) on the electret is a measure of time integrated 222Rn exposure. An E-PERM of 220-mL volume with an electret of 0.23 cm thickness gave a surface potential drop of 2.5 V for 37 Bq m-3 d (1 pCi L-1 d). The electret voltage was measured with a specially built surface potential voltmeter. This sensitivity was found adequate for a 1-wk measurement of 222Rn in homes. For longer term measurements, an E-PERM of 40-mL volume and an electret of 51-micron thickness was developed which gave a surface potential drop of 2.6 V for 37 Bq m-3 y (1 pCi L-1 y). Other combinations of chamber volume and electret thicknesses gave responses between these two values. The surface potential of electrets made from Teflon FEP were shown to stay stable even under extreme conditions of relative humidity. The ion collection process in E-PERMs was also shown to be independent of humidity down to an electret surface potential of 100 V.

Solar Irradiance Change and Special Longitudes Due to r-Modes.

Sluggish global oscillations, having a periodicity of months and trapped in the sun's convection zone, modulate the amount of energy reaching Earth and seem to impose some large-scale order on the distribution of solar surface features. These recently recognized oscillations (r-modes) increase the predictability of solar changes and may improve understanding of rotation and variability in other stars. Most of the 13 periodicities ranging from 13 to 85 days that are caused by r-modes can be detected in Nimbus 7 observations of solar irradiance during 3 years at solar maximum. These modes may also bear on the classical question of persistent longitudes of high solar activity.

Initial solar irradiance determinations from nimbus 7 cavity radiometer measurements.

Preliminary results from solar radiation measurements from the earth radiation budget experiment on the Nimbus 7 satellite yield a mean value of 1376.0 watts per square meter for the "solar constant" from 16 November 1978 to 15 May 1979. The observed variability (root-mean-square deviation) is +/- 0.73 watt per square meter (+/- 0.05 percent) for the period.

Rocket calibration of the Nimbus 6 solar constant measurements.

Total solar irradiance was observed simultaneously outside the earth's atmosphere by three types of absolute cavity radiometers and duplicates of four of the Nimbus 6 Earth Radiation Budget (ERB) solar channels in a June 1976 Sounding Rocket Experiment. The preliminary average solar constant result from the cavity radiometers is 1367 W m(-2) with an uncertainty of less than +/-0.5% in SI units. The duplicate ERB channel 3 on the rocket gave a value of 1389 W mm(-2) which agreed exactly with the Nimbus 6 ERB channel 3 measurement made simultaneously with the rocket flight. Therefore, Nimbus 6 ERB solar constant values should be reduced approximately 1.6% in order to convert the values to SI units.

Radiometric calibrations for the Earth radiation budget experiment.

The earth radiation budget (ERB) experiment is scheduled to be flown aboard the NIMBUS F satellite that is to be launched in mid-1974. This experiment includes channels, to measure solar radiation, earth-reflected radiation (albedo), and earth-emitted long-wave radiation. The calibration techniques and the standards employed are included in the topics of this paper. Problems associated with achieving the desired levels of confidence for a multifaceted, high accuracy satellite experiment are discussed and some results of preliminary calibrations are presented.

An absolute calibration source for laboratory and satellite infrared spectrometers.

A compact blackbody source with an operating range of -40 degrees C to + 60 degrees C, utilizing thermoelectric heat pumping for uniform and stable temperature control, has been developed. The blackbody radiator (target) consists of a blackened honeycomb cavity array coupled to four matched, two-stage (cascade type) thermoelectric modules. This array, located within a temperature-regulated baffle system, produces a blackbody of high emissivity (>0.995) with small thermal gradients over the source area (65 cm(2)). Heat pumping of the target and baffles is controlled, independently, by two interference-free, proportional regulators which provide linear thermal control in both the heating and cooling modes of operation. Additional features of this blackbody source include excellent stability and rapid response to input temperature changes. Provisions are made for temperature monitoring at five locations on the target and at the center of each of the four baffle units. Performance characteristics and test results obtained in nonabsorbing atmospheres and under vacuum conditions are presented, as are the details of construction and operation.