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Background. Primary hyperoxaluria (PH) is a rare autosomal recessive condition characterised by defects in the metabolism of glyoxylate which leads to excess oxalate production. It is an important disease to diagnose as it can progress to kidney failure (KF). Objective. To describe the characteristics, diagnosis and management of PH in South Africa and to identify any determinants of KF and death. Method. A retrospective study of all children younger than 16 years of age, diagnosed with PH at the Paediatric Renal Unit, Chris Hani Baragwanath Academic Hospital, from 1984 - 2017. Results. A total of 24 patients were identified, of which 20 records were available for complete analysis. The median age of presentation was 6.0 years. The common clinical presentations were urolithiasis (90%), KF (85%), nephrocalcinosis (75%), urinary tract infections (55%) and haematuria (30%). Nephrocalcinosis was better detected on abdominal radiograph compared with ultrasonography. Both nephrocalcinosis (p=0.009) and haematuria (p=0.018) were significantly associated with KF. Five patients had A112D genetic mutation in the AGXT. Fourteen received dialysis and four were transplanted. The mortality rate in this study was 58.3%. Conclusion. Clinicians should have a high index of suspicion for PH in patients presenting with haematuria, urolithiasis and KF. This study supports the measurement of urine oxalate levels and abdominal radiographs in screening for PH in children presenting in KF.

Acrylonitrile–butadiene–styrene (ABS) is one of the most widely usedindustrial thermoplastic and it is the most common material used in fused deposition modeling (FDM) technology. While FDM is one of the most used additive manufacturing (AM) technology commonly employed formodeling, prototyping, and manufacturing applications, the major research issues have been to balance ability to produce aesthetically appealinglooking products with functionality. It is therefore critical to know the mechanical properties of these parts, which, is as expected different from their nominal values.A FDM manufactured part has an internal channel referred to as infill. This internal build pattern has different mechanical properties than the same shaped part without the internal channel. This paper aims to define the effect of specimen mesostructure on the monotonic tensile behavior of ABS parts manufactured by FDM. The experiment uses the uPrint SE 3D printer to produce samples from ABS thermoplastic. The samples are tested following a modified form of ASTM D638 standard for plastic. The printed pieces are tested to failure using an Instron testing machine, and a strain gage extensometer that measures the amount of elongation in the pieces until failure. These standardized pieces are compared to know values of traditionally manufactured materials. This test shows the strength loss of materials through the 3D printing process compared to traditional manufacturing methods. The experiment for plastics is designed around two key criteria, orientation of the pieces, and the percent of infill during the printing process. It was found that a value of maximum strength, of 3D printed ABS, was approximately 92% of accepted values for the material, with a certainty of 5%. The study also shows that the bonds between layers are only 79% as strong as an axil loading along the layers.

The prevalence of neural tube defects (NTDs) in India is high in comparison to other regions in the world, with the Northern part reporting the highest prevalence.To explore the risk factors for NTDs, a case-control study was carried out in Delhi from January 2008 to June 2011. Using multivariate logistic regression model analysis, 308 cases were compared with 580 controls and adjusted odds ratio (AOR) was calculated using SPSS version 17.Maternal factors that were significantly associated with increased risk of NTDs were inter-pregnancy interval (AOR = 3.175; 95% confidence interval [CI], 2.007-5.024), hyperthermia during the first trimester (AOR = 2.07; 95% CI, 1.131-3.788), maturation ill pregnancy (AOR = 1.956; 95% CI, 1.385-2.763), chronic illness (AOR = 1.648; 95% CI, 1.103-2.462), and use of antibiotics (AOR = 5.589; 95% CI, 1.789-17.455). Differences in the risk were also found between upper and lower NTD. It was observed that all of the former five variables, except for chronic illness, were associated with risk for upper NTDs (AOR = 1.532; 95% CI, 0.916-2.563). In contrast, hyperthermia before conception (and not during the first trimester) was found to be additionally associated with risk for lower NTDs (AOR = 2.782; 95% CI, 1.302-5.944).These findings highlight heterogeneity in the etiology of upper and lower NTDs. The study also highlights the risk factors that should be considered in combating the risk of NTDs. Birth Defects Research 109:1393-1399, 2017.© 2017 Wiley Periodicals, Inc.

Earlier airplane fuselages were made primarily of aluminum alloy sheets, which have very good electrical conductivity. If lightning strikes an aluminum alloy surface, the current generated by the lightning can easily flow without interruption or diversion to the interior of the aircraft. Today, fiber-reinforced polymer composites have been widely utilized in aircraft. In order to protect fiber-reinforced composites against lightning strikes, copper (Cu) and aluminum (Al) meshes or metal sheets are used in the uppermost layer. As it is known, carbon fibers are nobler than both Cu and Al meshes, resulting in galvanic corrosion when these dissimilar materials interact with each other under certain environmental conditions. Consequently, corroded metal mesh areas will lose conductivity on the composite surface. For this reason, lightning strike protection is vitally important for the new generation of composite aircraft. In the present study, we systematically studied the galvanic corrosion effects of carbon fibers and metal (Al and Cu) meshes in acidic and salty conditions. We found that environmental conditions had a big impact on the galvanic corrosion between carbon fibers and metal meshes used for fiber-reinforced composites. This paper discusses current lightning strike protection techniques and provides some experimental evidence of graphene and indium-doped tin oxide (ITO)-based nanocomposite coatings on carbon fiber-reinforced composites. This approach may overcome the problem of lightning strikes on composite aircraft and may be useful for redesigning the new generation of composite aircraft.

Aim In 2002 the ACC/AHA guidelines for the management of patients with unstable angina (UA) and non-ST-segment elevation myocardial infarction (NSTEMI) were updated. We aimed to answer whether the implementation of updated guidelines was capable of influencing short- and long-term mortality in these patients. Methods We analyzed data on 812 consecutive patients who were admitted with either UA or NSTEMI between 2001 and 2004. Patients admitted in the two years before the implementation of updated guidelines (UA 01/02 group and NSTEMI 01/02 group) were compared to patients admitted in the two years thereafter (UA 03/04 group and NSTEMI 03/04 group). Yearly follow-up concerning all-cause mortality was obtained up to four years. Results The rate of revascularizations, the percentage of procedures performed within 48h of admission, and the administration of clopidogrel increased significantly. However, still many – especially high-risk – patients did not receive revascularization. Patients of both UA groups had an identical in-hospital mortality rate. Differences in mortality between groups gained statistical significance over time (four-year mortality; 15.1% for the UA 03/04 group vs. 26.5% for the UA 01/02 group, p=0.014; HR 0.49 95% CI 0.28–0.87). In patients with NSTEMI in-hospital mortality decreased from 18.4% in the NSTEMI 01/02 group to 9.6% in the NSTEMI 03/04 group (p=0.011; HR 0.47 95% CI 0.26–0.84), and 1-year mortality from 34.7% to 25.1% (p=0.038; HR 0.63 95% CI 0.41–0.98), respectively. Mortality rates beyond one year were still lower in the NSTEMI 03/04 group as compared to the NSTEMI 01/02 group but it did not reach statistical significance. Multivariate Cox-regression analysis revealed furthermore that also patients with higher age and/or renal dysfunction benefit from an early invasive strategy. Conclusion The implementation of updated guidelines for NSTE-ACS had significant impact on short- and long-term mortality. However, an early invasive strategy is still withheld to a significant number of high-risk patients, who would benefit from an invasive treatment.

The use of fiber reinforced polymer (FRP) composites in the aircraft and automotive industries exponentially. Reinforced fibers which are abrasive in nature make it hard to machine by the traditional machining. Dissipation of heat into workpiece which in turn results in enhanced cutting tool wear and damage to the workpiece is the common problems faced in traditional machining of FRPs. Nontraditional machining is favorable to reduce these issues. Abrasive waterjet machining (AWJM) is one of the best choices for machining FRPs. Development in AWJM of FRPs and the current research in this field will be discussed in details. Machining process of FRPs, quality dependents such as surface finish and variable cutting parameters will be addressed. One of main issues in AWJM noise due to high flow rate of water jet will be addressed. The importance of human safety aspects when AWJM is employed will be highlighted. Limitations and challenges in AWJM are presented elaborately.

Machining of fiber reinforced composites is an important activity in the integration of these advanced materials into engineering applications. Machining damage due to excessive cutting forces may result in rejecting the composite components at the last stages of their production cycle. Therefore, the ability to predict the cutting forces is essential for selecting process parameters that would result in minimum machining damage. This work utilizes mechanistic modeling techniques for simulating the cutting of carbon fiber-reinforced polymers (CFRP) with a helical end mill. A methodology is developed for predicting the cutting forces by transforming specific cutting energies from orthogonal cutting to oblique cutting. It is shown that the method developed is capable of predicting the cutting forces in helical end milling of unidirectional and multidirectional composites and over the entire range of fiber orientations from 0° to 180°. This is a significant improvement over previous models that were only capable of addressing orthogonal cutting and/or a limited range of fiber orientations. Model predictions were compared with experimental data and were found to be in good agreement in cutting unidirectional laminate, but with lesser agreement in the case of a multidirectional laminate.

Knowledge sharing has attracted considerable interest in the context of the multinational corporation. However, although there is evidence to support the view that effective knowledge sharing is fundamental for competitive advantage, we still do not understand clearly enough the enablers and barriers to such knowledge sharing. In this paper, we argue that interpersonal similarity is one key driver behind knowledge sharing within the MNC context. We focus on the similarity of the national-cultural background, shared language, and similarity of organizational status as factors generating homophily. We suggest that such similarity leads to a higher tendency for interaction, increasing the sharing of business knowledge, and driving an aggregate effect of clustering. Based on a synthesis of the literature and a multiple case study of three multinationals, we argue that knowledge flows better within clusters driven by homophily than between them, creating a paradox of homophily.

Four new alkaloids, characterized as 6-(2-hydroxyethyl)-5,6-di-hydrosanguinarine (1), 6-acetonyl-5,6-dihydrosanguinarine (2), N-methyl-2,3,7,8-tetramethoxy-5,6-dihydrobenzophenanthridine-6-ethanoic acid (3), N-methyl-2,3,7,8-tetramethoxy-6-oxo-5,6-dihydrobenzophenanthridine (4), together with oxosanguinarine (5), spallidamine (6), 6-acetonyl-5,6-dihydrochelerythrine (7), 6-oxochelerythrine (8) and sanguidimerine (9) were isolated from the roots of Corydalis flabellata.

The one step annular dimerisation of naturally occuring linear furanocoumarins has been effected in 70–85% yield by PPA-SiO2.

Three new triterpenoids, designated as koelpinin-A, B and C and characterised as 28-nor-lup-12,17-dien-3 beta,16 alpha-diol,3 beta-acetoxy-28-nor-lup-12,17-dien-16 alpha-ol and 28-nor-lup-12,17-dien-3 beta-ol-16-one, respectively, together with 30-nor-lup-3 beta-ol-20-one, taraxeryl acetate and germanicol, were isolated, from the aerial parts of Koelpinia linearis. 13C-NMR shifts were assigned after performing APT and DEPT experiments.

Direct digital manufacturing (DDM), is advancing rapidly in capability and commercial potential. Directly from CAD data, parts are manufactured without traditional cutting, forming or casting methods. Some of the main developments of the recent past in DDM are discussed in this article. Microstructural and property data will be presented for each type of process, illustrating the benefits and limitations of direct digital manufacturing on various materials, and focusing on emerging and projected applications of metal and ceramic materials by direct digital manufacturing. The review is based on an extensive literature review covering academic publications, company documents and web site information.Copyright © 2012 by ASME

Machining of fiber reinforced polymer (FRP) composites is a major secondary manufacturing activity in the aircraft and automotive industries. Traditional machining of these composites is difficult due to the high abrasiveness nature of their reinforcing constituents. Almost all the traditional machining processes involve in the dissipation of heat into the workpiece which can be resulted in damage to workpiece and rapid wear of the cutting tool. This serious issue has been overcome by water jetting technologies. Abrasive waterjet machining (AWJM) is a nontraditional method and one of the best options for machining FRPs. This paper presents a review of the ongoing research and development in AWJM of FRPs, with a critical review of the physics of the machining process, surface characterization, modeling and the newer application to the basic research. Variable cutting parameters, limitations and safety aspects of AWJM and the noise related issues due to high flow rate of water jet will be addressed. Further challenges and scope of the future development in AWJM are also presented in detail.

Fiber reinforced polymer (FRP) composite products offer many significant environmental benefits such as light weight, superior mechanical properties, extended service life, low maintenance and resistance to corrosion. But until now it has been difficult to compare sustainability of different FRP materials and production for processes. Concern for the environment, both in terms of limiting the use of finite resources and the need to manage waste disposal, has led to increasing pressure to recycle materials. This paper focuses on two issues that must be addressed to ensure continued growth in FRP usage is the disposal of waste generated during product manufacturing and the disposal of the products at the end of their useful life. The major cost drivers for FRPs are labor and raw materials. The use of recycled FRPS offers low-cost raw materials. This paper presents a review of the current status and outlook of FRP composites recycling and re-manufacturing techniques. A future vision for the use of FRP composites with sustainability applications is underway at many university research institutes and in industries. This paper will also state the sustainability problems of fiber reinforced composite products, and potential solutions.Copyright © 2011 by ASME

It is widely recognized that industrial production inevitably results in an environmental impact. Energy consumption during production is responsible for a part of this impact, but is often not provided in cradle-to-gate life cycles. Transparent description of the transformation of materials, parts, and chemicals into products is described herein as a means to improve the environmental profile of products and manufacturing machine. This paper focuses on manufacturing energy and chemicals/materials required at the machine level and provides a methodology to quantify the energy consumed and mass loss for simple products in a manufacturing setting. That energy data are then used to validate the new approach proposed by (Overcash et.al, 2009a, and 2009b) for drilling unit processes. The approach uses manufacturing unit processes as the basis for evaluating environmental impacts at the manufacturing phase of a product’s life cycle. Examining manufacturing processes at the machine level creates an important improvement in transparency which aids review and improvement analyses.

Nanomaterials and nanomanufacturing is one of the fast growing and interesting fields in recent research and industries, and gaining huge interest around the world. As the nanomaterials has a higher physical and mechanical properties compared to their metal counterparts, it is expected that significant amount (15–20%) of nanomaterials will be put into use in less than five years periods almost in all fields of manufacturing. As the nanomaterial manufacturing is new, it is essential to establish an optimal method so as to reduce wastages and to increase the ratio of output to input materials used. It’s important to use the minimal energy, water and other raw materials. Thus, this review will more concentrate on the sustainability of inputs, need to improve or optimize the production methods or sustainable manufacturing and green gas production and its global effects. Suitability of both top-down and bottom-up processing for nanoparticles will be addressed. Need of life cycle analysis to understand feasibility of recyclable at the end of the life with least possible wastage and reduced energy. Current research on environmental benefits and risk of potential toxicity and health effects of nanoproducts will be discussed.

From the rhizomes of the Iris kashmiriana , two new isoflavones, isocladrastin and kashmigenin, were characterized as 3′-hydroxy-6,7-4′-trimethoxy-isoflavone and 4′-hydroxy-3′,5′-dimethoxy-6,7-methylenedioxy-isoflavone, respectively. Also, junipegenin-B has been found present in this plant species.

Three new triterpenoids, designated as koelpinin - A, B and C and characterised as 28-nor-lup-12,17-dien-3β,16α-diol,3β-acetoxy-28-nor-lup-12,17-dien-16α-ol and 28-nor-lup-12,17-dien-3β-ol-16-one, respectively, together with 30-nor-lup-3β-ol-20-one, taraxeryl acetate and germanicol, were isolated, from the aerial parts of Koelpinia linearis. 13 C -NMR shifts were assigned after performing APT and DEPT experiments.

The one step annular dimerisation of naturally occuring linear furanocoumarins has been effected in 70–85% yield by PPA-SiO2.

Rapid access to or generation of life cycle information is a potentially valuable tool for the design of products to meet the needs of sustainability improvement. A new approach is developed to use the manufacturing unit process, commonly outlined in manufacturing process taxonomy systems, as the basis for life cycle inventory. This will initially involve 50–70 unit processes from the taxonomy and will generate energy and mass profiles for each unit process life cycle (uplci). These uplci can be adjusted for each case to include the major variables affecting such operations as related to any specific product. The sum of the performance of a sequence of uplci thus provides the life cycle of the specific product from a defined set of plant process inputs.Copyright © 2009 by ASME

Computer tomographic (CT) studies and anthropological measurements were performed in individuals showing complete or partial atlanto-occipital fusion. In 13 patients and 13 matched controls all measurements excepting head length and head breadth gave smaller, and in some instances significantly smaller values in the patients. The two head measurements, on the other hand, turned out to be somewhat, though not significantly larger. This suggested a certain amount of hydrocephalus internus. Computer-tomographic (CT) studies in 11 patients and 9 controls gave some--not very clearcut--evidence in favor of this hypothesis. Moreover, some other mild anomalies such as prominent and dilated sulci and cisterns were observed in 9 of 11 patients and in 3 of 9 controls (P1 one tailed = 0.0399).

Objectives: This study sought to investigate gender-related differences in patients with atrial fibrillation (AF) in Europe. Background: Gender-related differences may play a significant role in AF. Methods: We analyzed the data of 5,333 patients (42% female) enrolled in the Euro Heart Survey on Atrial Fibrillation. Results: Compared with men, the women were older, had a lower quality of life (QoL), had more comorbidities, more often had heart failure (HF) with preserved left ventricular systolic function (18% vs. 7%, p < 0.001), and less often had HF with systolic dysfunction (17% vs. 26%, p < 0.001). Among patients with typical AF symptoms (56% of women, 49% of men), there was no gender-related difference in the choice of rate or rhythm control. Among patients with atypical or no symptoms (44% of women, 51% of men), women less frequently underwent rhythm control (39% vs. 51%, p < 0.001) than did men. Women underwent less electrical cardioversion (22% vs. 28%, p < 0.001). Prescription of oral anticoagulants was identical (65%) in both genders. One-year outcome was similar except that women had a higher chance for stroke (odds ratio 1.83 in multivariable regression analysis, p = 0.019). Conclusions: Women with AF had more comorbidities, more HF with preserved systolic function, and a lower QoL than men. In the large group with atypical or no symptoms, women were treated appropriately more conservatively with less rhythm control than men. Women had a higher chance for stroke. Long-term QoL changes and other morbidities and mortality were similar. © 2007 American College of Cardiology Foundation.

Fiber reinforced polymers are widely used in the transportation, aerospace and chemical industries. In rare instances these materials are produced net-shape, and secondary processing such as machining and assembly may be required to produce a finished product. Because fiber reinforced polymers are heterogeneous materials, they do not machine in a similar way to metals. Thus, the theory of metal machining is not valid for the analysis of machining of fiber- reinforced composites. Previous attempts in modeling this problem have adopted Merchant's theory from metal cutting by assuming that chip formation takes place in a shear plane which inclination angle is determined by the minimum energy principle. This class of models showed that model predictions are valid only for fiber orientations less than 60°. The work presented here focuses on providing predictive models for the cutting forces in unidirectional composites. The models are based on the specific cutting energy principle and account for a wide range of fiber orientations and chip thickness. Results from two forms of non-linear modeling methods, non-linear regression and committee neural networks, were compared. It was found that committee neural networks provide better prediction capability by smoothing and capturing the inherent non-linearity in the data. The model predictions were found to be in good agreement with experimental results over the entire range of fiber orientations from 0 to 180°.

From the rhizomes of the Iris kashmiriana , two new isoflavones, isocladrastin and kashmigenin, were characterized as 3′-hydroxy-6,7-4′-trimethoxy-isoflavone and 4′-hydroxy-3′,5′-dimethoxy-6,7-methylenedioxy-isoflavone, respectively. Also, junipegenin-B has been found present in this plant species.

An erratum has been published for this article in Prenatal Diagnosis 23 (3) 2003, 268. Objectives Analysis of a referral population of patients with choroid plexus cysts (CPCs) was performed to compare an average risk method of counseling to an individualized risk method. Methods A total of 395 patients referred to a Prenatal Diagnosis Center were included, of whom 341 had isolated CPCs and 54 had associated ultrasound abnormalities. For isolated CPCs, an average risk of 1/150 for aneuploidy was compared to an individualized risk assessment [prior risk as determined by maternal age or serum screening multiplied by the likelihood ratio established by Gupta et al. (1997)]. Accuracy, cost, and procedure-related losses were assessed. Results Both methods resulted in 100% sensitivity. The individualized method resulted in greater specificity, decreased costs, and (theoretically) fewer procedure-related pregnancy losses. Conclusions An individualized risk method of counseling utilizing the likelihood ratios established by Gupta et al. (1997) was superior to an average risk method for assessing trisomy 18 risk in the setting of CPC detected in mid-trimester. Copyright © 2002 John Wiley & Sons, Ltd.

Two new nortriterpenes have been isolated from Phlomis spectabilis and characterised as 28-noroleana-16,21-diene-3α,19α,23,29-tetrol and 28-noroleana-16,21-diene-3α,19α,29-triol-23-al.

Histoplasmosis is a progressive granulomatous disease caused by the intracellular dimorphic fungus Histoplasma capsulatum. We report a rare case of esophageal histoplasmosis in a renal allograft recipient. A 55-year-old male who received a live, unrelated renal allograft 20 years ago presented with complaints of recurrent fever for ten to 12 months, weight loss over six months, progressive dysphagia more for solids for five to six months and joint pain and swelling involving the bilateral metacarpo-phalangeal and proximal interphalangeal joints. Biopsy from the esophageal ulcers revealed dense inflammation infiltrated with lymphocytes and macrophages with clusters of strongly positive intracellular fungal spores with a clear area or "halo-like" zone suggestive of Histoplasma capsulatum invasion. The patient was treated with intravenous liposomal amphotericin B for ten days and later switched over to oral itraconazole. Repeated endoscopy revealed significant improvement of the lesions.

An unusual series of five long-chain alkanoic acid (C 14 C 18 ) esters of lupeol was isolated from the methanol extract of koelpinia linearis and characterized by chemical and spectroscopic methods, including 13 C NMR. The spectral assignments were achieved by APT and DEPT techniques.

Recently Dhar et al. reported the isolation of two new steroidal lactones from the leaves of Datura quercifolia HBK and formulated them as 5α,12α,17α-trihydroxy-1-oxo-6α, 7α-epoxy-22 S -witha-2,24-dienolide and 5α,17α-dihydroxy-1, 12-dioxo-6α,7α-epoxy-22 S -witha-2,24-dienolide on the basis of UV, IR, NMR and MS studies. Further detailed chemical and spectral studies have led to revised structures, namely 5α, 12α-dihydroxy-1-oxo-6α,7α: 24α, 25α-diepoxy-20 S , 22 R -with-2-enolide and 5α-hydroxy-1, 12-dioxo-6α, 7α: 24α, 25α-diepoxy-20 S , 22 R -with-2-enolide, respectively, for the above two compounds.

From the petrol extract of Swertia petiolata a new natural triterpene, 3β-hydroxylup-13(18)-ene has been isolated in addition to 3β-hydroxylup-12en-28-oic acid and ursolic acid.

Water bodies up to 0.9 ha surface area, which are indistinguishable by Landsat Multispectral Scanner (MSS) due to the latter's poor spatial resolution of 80 m, can be identified and mapped reliably and reasonably within ±10% accuracy by Landsat Thematic Mapper (TM) false colour composite because of its higher spectral and spatial resolution of 30 m. Comparative study of Landsat TM and the Survey of India topographical maps revealed reductions in the water surface and drainage basin areas up to 1.8 to 2.4 and 6.0 to 8.0 times, respectively, over a period of 28 years (1958–1986) due to the biotic interference resulting in desertification in the large adjoining areas.

Skin reflectances were obtained at 426, 550 and 685mg wavelengths (employed in the E.E.L.spectrophotometer) from medial arm and forehead sites among 414“Baniya”males to study the changes in skin pigmentation with age during 10-16 years-an important growth period. It was not possible to arrive at any general conclusion using together the three reflectance scales-Log R426mμ, R550mμ, and“Anti-log”R685mμ, because they exhibited some significant differences in their results“Anti-log”R685mμ, scale was finally adopted to study this problem.The observations for the unexposed medial arm site were used as indicator of the changes in skin colour with age. It was found that during the period between 10 and 16 years, the males first exhibit an increase in the pigmentation which is then lost through the adolescent years even to a significant extent.The forehead pigmentation was found to increase with age, so also was the forehead tanning but it is realised that from such studies it would be difficult to demarcate the effect of age on skin tanning

Age changes in human skin pigmentation have been observed by Garn et al. (1956), Walsh (1964), Huizinga (1965), Omoto (1965), Mazess(1967),Tiwari & Kalla (1968 and 1969), Kalla (1969) and Conway & Baker (1972). Though these investigations were confined to only few populations, the informations yielded by them are quite interesting and proclaim careful further studies of this problem in different populations. Recently it has been suggested (Kalla & Tiwari, 1970) that the phenomenon of ageing may also be an important factor in influencing the sex differences in human skin pigmentation. The present article tends to focus some light on this aspect of the problem. The data consists of skin reflectances obtained at 685 milimicron wavelength from the medial arm site of 414 "Aggarwal" boys and 371 "Aggarwal" girls be tween 10 and 16 years of age. "Aggarwal" is an endogamous group of north India. The sample is drawn from Delhi. The skin reflectances were obtained with the help of an EEL spectrophotometer (Weiner, 1951), with due precautions (Kalla, 1968). The EEL spectrophotometer employs nine wavelengths. 685 mili-micron wavelength was selcted because the skin reflectance at this wavelength is found to bear a linear reciprocal relationship with the amount of melanin in skin (Harrison & Owen, 1956/57), and it is melanin which is chiefly responsible for variation in human skin colour (Edwards & Duntley, 1939). As suggested by Harrison & Owen (1964), the skin reflectance at 685 mili-micron wavelength is transformed into its "anti-log". The agewise "anti-log" reflectance values and their variances have been set out in Tab. 1, and the age curves through the mean values have been drawn in Fig. 1. Comparable parts of the curves for the Tibetans (Tiwari & Kalla, 1968) have been superimposed in this figure to enable a comparative evaluation.

SummarySkin reflectances were obtained at 685 mμ wave length from the medial upper arm and the forehead regions among 105 Tibetan males and 105 Tibetan females, in order to study sex differences in human skin pigmentation. The forehead pigmentation of males was always found to be darker than that of females, and the difference to be significant during middle and late adolescence The medial upper arm pigmentation of girls was found to be darker than that of boys, during early adolescence; but during middle adolescence the two sexes exhibited just similar pigmentation and during late adolescence females emerged to be significantly lighter than males. The present study, thus, suggests that one of the factors causing sex differences in human skin pigmentation may be the physiological changes occurring during adolescence, which may be genetically determined.

Experiment has been conducted upon 91 adult males by irradiating their medial upper arm sites with a standard dose of polychromatic ultraviolet irradiations emitted by the Philips U.V.lamp, and measuring the induced pigmentation with the help of an E.E.L.spectrophotometer, in order to study the tendency of the variation in skin tanning with the variation in initial melanin pigmentation of skin.It is found that despite the high variability in the maximum skin tanning so produced among the individuals even at similar initial pigmentary level, the skin tanning, on average, tends to increase with the increase in initial pigmentation up to a certain level of initial pigmentation.A further increase in the initial melanin concentration of skin, then, causes a slight but gradual lowering of the skin tanning.It is further found that in the initially heavily pigmented skins, an increase in initial pigmentation tends to lower even the threshold time of the maximum skin tanning.The frequency distribution of the threshold time of the maximum skin tanning by the present amount of irradiation, has also been discussed.

A Philips U. V. lamp (for U. V. irradiations) and an E.E.L. spectrophotometer (for measurement of melanin pigmentation of skin) were used to study the existence of any genetical differences in the skin tanning capacity in the males of four Indian caste groups, namely the Arora, the Baniya, the (bengali) Brahman and the Kayastha (Saxena). It was found that only the Arora and the Baniya show genetical differences in skin tanning capacity while the rest don't.

Families of 20 probands with atlanto-occipital fusion were studied, and the neurological complications in these patients described. In X-ray studies of 115 close relatives, 4 additional cases (3.5%) with the same anomaly were detected. In a comparison of adult patients with closely related age- and sex-matched controls, all anthropological measurements except length and breadth of the head tended to be smaller in the patients; for height, weight, leg and foot length, and the robusticity index, these differences were statistically significant.

The medial arm region of 38 individuals of 8 families (children: 15 male and 7 female, and 8 parental couples) belonging to an endogamous caste group (Saxena Kayastha) of Delhi, was irradiated with a regulated dose of ultra-violet rays from a polychomatic U.V. lamp. Skin reflectances before and after the irradiation were obtained withthe help of EEL reflectance spectrophotometer, Observations on skin reflectance were made every 24 hrs after irradiation of the skin for 10 consequtive days. The recording of the maximum drop in the skin reflectance, as a consequence of U.V. irradiation, was thus ensured. An assessment of skin tanning potential was made with the help of these observations. Sex differences (estimated using parental data only) and parent-child correlation were studied with respect to skin tanning potential. Sex differences in skin tanning potential are found to be indiscernable in the sample. However, in skin tanning potential the parent-child correlation is found to be much higher than in the normal skin pigmentation: this seems to suggest a stricter genetic control of skin tanning potential than of normal skin pigmentation.

Four flavonol glucosides, one new, have been isolated from a methanolic extract of Phlomis spectabilis . Their structures were established as the 3-glucosides and 3-(6″-( E )- p -coumaroyl)glucosides of kaempferol and of kaempferol 7,4′-dimethyl ether.

Two novel isomeric hopene triterpenes, Swertialactone C and Swertialactone D have been isolated from Swertia petiolata. Their structures were established as 2,3-seco-2 → 3 lactone, 1β,3β-epoxy-hop-17(21)-ene and 2,3-seco-2 → 3 lactone, 1β,3β-epoxy-hop-16-ene, respectively.

A new isoflavone, 5,7-dihydroxy-6,2′-dimethoxyisoflavone, together with iristectorigenin A and iristectorin A were isolated and characterized from the methanol extract of Iris spuria .