Point Count System Research Articles

Volumetric study on sheep brain using stereology technique

AbstractThree‐dimensional morphometric data better show the structural and functional characteristics of the brain. The objective of this study was to estimate the volume of the cerebral structures of the sheep using design‐based stereology. The brains of five sheep were used, fixed in formalin 10% and embedded in agar 6%. An average of 10–12 slab was obtained from each brain. All slabs were stained using Mulligan's method and photographs were recorded. The volume of the brain and its structures were estimated using the Cavalieri's estimator and the point counting system. The total volume was 70604.8 ± 132.45 mm3. The volume fractions of the grey and white matters were calculated as 42.55 ± 0.21% and 24.23 ± 0.51% of the whole brain, respectively. The fractional volume of the caudate nucleus and claustrum were estimated at 2.39 ± 0.08% and at 1.008 ± 0.057% of total brain volume. The volumes of corpus callosum, internal capsule and external capsule were 1.24 ± 0.053%, 3.63 ± 0.22% and 0.698 ± 0.049% of total cerebral volume, respectively. These data could help improve the veterinary comparative neuroanatomy knowledge and development of experimental studies in the field.

Three-dimensional morphometry of kidney in New Zealand rabbit using unbiased design-based stereology.

The rabbit is widely used as a laboratory animal in experimental models of kidney diseases. This species is also important from a veterinary perspective as a companion animal. Stereology has been accepted as an accurate approach to kidney morphometry. The objective of the present project was to provide normal quantitative stereological parameters for adult rabbit kidneys. The left kidneys of five adult male New Zealand rabbits were used. Isotropic sections were obtained using the orientation method. Total kidney volume was calculated by the Cavalieri principle. The volume fraction of the renal structures was estimated using the point counting system. The lengths of the proximal convoluted tubule (PCT) and distal convoluted tubule (DCT) were calculated using counting frames. The total glomerular number was accounted for using the physical/fractionator technique. The mean glomerular volume was obtained by dividing the total volume of glomeruli by their total number. The total volume of rabbit kidneys calculated was 10.39 ± 1.98 cm3. The fractional volume of the kidney cortex and medulla accounted for 57.79 ± 0.65% and 42.2 ± 0.65%, respectively. The total glomerular volume was 2.18 ± 0.32% of the whole kidney. The total number of glomeruli in the rabbit kidney was estimated as 204.68 ± 12 × 103. The mean glomerular volume measured 1.07 ± 0.12 × 106 μm3. The total length of PCT and DCT was 2.96 ± 0.29 km and 1.38 ± 0.24 km, respectively. These findings can be used as a reference in experimental nephrology research and may help to expand the knowledge of nephrology in mammals by comparing with available data on humans and other species. RESEARCH HIGHLIGHTS: Three-dimensional morphometry of adult rabbit kidney structures was analyzed using quantitative stereology. Total volume of kidney, fractional volume of cortex and medulla, length of renal tubules and number of nephrons were estimated. These three-dimensional morphometrical data can be used as a reference in experimental nephrology research and may help to expand the knowledge of nephrology in mammals.

Three-dimensional morphometry of the testis in dog using design-unbiased stereology.

Testis is considered the main organ of the male reproductive system. Dogs are used as a suitable experimental model of testicular diseases in humans. From the veterinary aspect, several disorders have been reported to affect the testis in dogs. Thus, the objective of the present study was to investigate the morphometrical features of the dog testis using design-based stereology. The testes of six male dogs were used. Isotropic, uniform random sections were obtained and processed for light microscopy. Testicular total volume and the fractional volume of the seminiferous tubules, interstitial tissue and germinal epithelium were measured using the Cavalieri's estimator and the point counting system. Germinal epithelial surface area was estimated using test lines, and total length of seminiferous tubules was analysed using the counting frames. The total volume of testis was calculated 13.64 ± 1.94 cm3 . The relative volume fractions of the seminiferous tubules, interstitial tissue and germinal layer expressed as a percentage of total testicular volume were found to be 75.87 ± 6.11%, 23.68 ± 5.15% and 64.15 ± 4.82%, respectively. The surface area of the germinal layer was 915.25 ± 150.48 cm2 . The thickness of germinal layer was estimated to be 96.18 ± 10.72 μm. The total length of seminiferous tubules measured 290.8 ± 35.86 m. No statistical difference in investigated parameters was found between the left and right testes (p > 0.05). Our data might contribute to the male reproductive knowledge, help develop experimental studies in this field and possibly lead to advancement in the diagnosis and treatment of testicular diseases in the dog.

Morphometric study of the testis in sheep embryos using unbiased design-based stereology.

Sheep have been used as translational models of human postnatal testicular development. However, the morphometric features of the normal developing testis in sheep embryos have not been previously investigated using stereology. The objective of the present work was to establish normal quantitative parameters for fetal testicular tissue components in sheep, using unbiased design-based stereological methods. Twenty-four sheep embryos were divided into four gestational age groups (9-11, 12-14, 15-17 and 18-20weeks of gestation) on the basis of the embryos' crown-rump length. Isotropic, systematic uniform random sections of the left testes were obtained by employing the orientator method. Testicular total volume, the absolute and proportional volumes occupied by the seminiferous tubules and interstitial tissue, as well as the seminiferous tubule length, were estimated using the point-counting system and the unbiased counting frame principle. All the parameters, with the exception of the interstitial tissue's fractional volume, gradually increased along with gestational age, with the maximum increase especially seen in the late fetal stages. The proportional volume of the interstitial tissue, on the other hand, showed a decreasing trend along with increasing gestational age. The absolute volume of the testes, of the seminiferous tubules and of the interstitial tissue, and the length of the seminiferous tubules showed a significant (p<0.05) positive linear correlation with gestational age. Several similarities were observed with human testicular embryogenesis. The stereological data emerging from the present study might prove useful as basic contribution to the fields of andrology and embryology and stimulate further research in these areas.

PEMETAAN POTENSI KERENTANAN PENCEMARAN AIR PERMUKAAN UNTUK PENGENDALIAN SANITASI LINGKUNGAN DI KABUPATEN BULELENG (Mapping on the potential vulnerability of surface water pollution for environmental sanitation control in Buleleng Regency)

One of the efforts to prevent water pollution is done by mapping of potential pollution vulnerability to support water quality control policy making. The research location is in Panas Sub-watershed, a part of the Saba Watershed which originates on the northwest slope of the Bratan Volcano Complex and upstream is Lake Tamblingan, Buleleng Regency. The objectives of the study include: 1) mapping the parameters of potential surface water pollution vulnerability, 2) mapping land cover changes in 2000 and 2016, 3) mapping the potential surface water pollution vulnerability and its dynamics in 2000 and 2016, and 4) formulating a management recommendation to control surface water pollution. Mapping the potential surface water pollution vulnerability was conducted by GIS and Point Count System Model (PCSM) method using parameters of slope, land cover, and annual average rainfall. The results showed that some of the upstream and middle areas of the Panas Sub-watershed were categorized as high potential vulnerability caused by steep slopes, plantation cover, and annual average rainfall of 2,251 - 2,500 mm/year. Various recommendations to control surface water pollution are conducting integrated waste management individually or in groups, such as collectively septic tank construction, waste disposal organization, and waste water management installation; providing directions for appropriate land cultivation for farmers so that the pollutant load due to the use of pesticides could be controlled; as well as controlling and supervising the tourist area around Tamblingan Lake.

Design-based stereological study of the guinea-pig (Cavia porcellus) cerebellum.

Guinea pigs have proved useful as experimental animal models in studying cerebellar anatomical and structural alterations in human neurological disease; however, they are also currently acquiring increasing veterinary interest as companion animals. The morphometric features of the normal cerebellum in guinea pigs have not been previously investigated using stereology. The objective of the present work was to establish normal volumetric and quantitative stereological parameters for cerebellar tissues in guinea pigs, by means of unbiased design-based stereology. Cerebellar total volume, gray and white matter volume fractions, molecular and granular layers volume fractions, cerebellar surface area, Purkinje cellular and nuclear volumes, and the Purkinje cell total count were stereologically estimated. For this purpose, cerebellar hemispheres from six adult male guinea pigs were employed. Isotropic, uniform random sections were obtained by applying the orientator method, and subsequently processed for light microscopy. The cerebellar total volume, the white and grey matter volume fractions, and the molecular and granular layer volumes were estimated using the Cavalieri's principle and the point counting system. The cerebellar surface area was estimated through the use of test lines; Purkinje cellular and nuclear volumes were analysed using the nucleator technique, whereas the Purkinje cell total count was obtained by means of the optical disector technique. The mean±standard deviation total volume of a guinea-pig cerebellar hemisphere was 0.11±0.01cm3 . The mean volumetric proportions occupied by the gray and white matters were, respectively, 78.0±2.6% and 22.0±2.6%, whereas their mean absolute volumes were found to be 0.21±0.02cm3 and 0.059±0.006cm3 . The volumes of the molecular and granular layers were estimated at 112.4±20.6mm3 and 104.4±7.3mm3 , whereas their mean thicknesses were calculated to be 0.184±0.020mm and 0.17±0.02mm. The molecular and granular layers accounted for 40.7±3.9% and 37.4±1.8% of total cerebellar volume respectively. The surface area of the cerebellum measured 611.4±96.8mm2 . Purkinje cells with a cellular volume of 3210.1µm3 and with a nuclear volume of 470.9µm3 had a higher incidence of occurrence. The mean total number of Purkinje cells for a cerebellar hemisphere was calculated to be 253,090±34,754. The morphometric data emerging from the present study provide a set of reference data which might prove valuable as basic anatomical contribution for practical applications in veterinary neurology.

Morphometrical study of the cat cerebellum using unbiased design-based stereology.

The objective of the present study was to investigate the morphometrical features of the cat cerebellum using design-based stereology. Cerebellar hemispheres from four male cats were examined. Isotropic, uniform random sections were obtained and processed for light microscopy. Cerebellar total volume (V), white (WM) and grey matter (GM) volume fractions, and the volumes of the molecular and granular layers were measured using the Cavalieri's estimator and the point counting system. Cerebellar surface area was estimated using test lines, and Purkinje cellular and nuclear volumes were analysed using the nucleator technique. The volume of the cat cerebellar hemispheres was 2.06±0.29cm3 . The relative volume fractions of the GM and WM were 70.6±2.6% and 29.3±2.6%, respectively. The surface area of the cerebellar hemisphere was 68.2±17.8cm2 . The volumes of the molecular and granular layers were estimated at 0.89±0.16cm3 and 0.56±0.1cm3 , respectively. The Purkinje cell volumes were found to be ranging from 1,717 to 28,489µm3 , of which cells with a perikaryon volume of 6,994µm3 had a higher incidence. The Purkinje nuclear volume was estimated at 440-3,561µm3 , and nuclei with a volume of 1,252µm3 were the most frequently occurring ones. Our data might contribute to the veterinary comparative neuroanatomy knowledge, help develop experimental studies in this field, and possibly lead to advancement in the diagnosis and treatment of nervous diseases in the cat.

Artificial Neural Network Architectures for Solving the Contract Bridge

Contract Bridge is an intelligent game, which enhances the creativity with multiple skills and quest to acquire the intricacies of the game, because no player knows exactly what moves other players are capable of during their turn. The Bridge being a game of imperfect information is to be equally well defined, since the outcome at any intermediate stage is purely based on the decision made on the immediate preceding stage. One among the architectures of Artificial Neural Networks (ANN) is applied by training on sample deals and used to estimate the number of tricks to be taken by one pair of bridge players is the key idea behind Double Dummy Bridge Problem (DDBP) implemented with the neural network paradigm. This study mainly focuses on Cascade-Correlation Neural Network (CCNN) and Elman Neural Network (ENN) which is used to solve the Bridge problem by using Resilient Back-Propagation (R-prop) Algorithm and Work Point Count System.

ANALISIS KONDISI AKTUAL PENCEMARAN MERKURI BERDASARKAN PETA KERENTANAN PENCEMARAN AIR PERMUKAAN PADA PENAMBANGAN EMAS RAKYAT DESA PANCURENDANG, KECAMATAN AJIBARANG, BANYUMAS

ABSTRACTThe mining and processing of people's gold produces impacts on the surrounding environment. Some residents immediately dumped the waste gold processing results into the environment. It is necessary to analyze the actual condition of mercury pollution based on a map of the level of pollution vulnerability to determine the size of the level of difficulty and the ease of polluted substances to affect surface water quality. The purpose of this study is to analyze the actual condition of the level of vulnerability of surface water pollution around the study area. The method used in this study is a survey method and field mapping, sampling methods: purposive sampling, laboratory analysis methods, mathematical methods, and descriptive evaluation methods. Calculation of the level of vulnerability of surface water is the PCSM (Point Count System Model) method with 3 parameters, namely land use, slope, and rainfall. Overlay is done between the level of pollution vulnerability map with the actual conditions of pollution in the field. The results showed the study area has a level of vulnerability to surface water pollution in the study area including the classification of quite vulnerable and very vulnerable. Based on the results of the study it can be concluded that the total score of 36-43 included in the vulnerability class is quite vulnerable. The total score of 43 - 50 is included in the very vulnerable vulnerability class. Actual mercury levels in the study area were known in a row AP1-AP6 samples were 0,00046 mg / L; &lt;0.00006 mg / L; &lt;0.00006 mg / L; &lt;0.00006 mg / L; 0,00039 mg / L and &lt;0,00006 mg / L. These results indicate that surface water in the study area has not been contaminated with mercury because its value is brought to all quality standards. Â

Effect of land use in seasonal abundance of Eared Dove (Zenaida auriculata) in Southwestern Brazil.

Changes at the landscape scale associated with expansion in agricultural land use and changes in agricultural practices are common causes of alteration in patterns of abundance and composition of avian communities. Eared Dove (Zenaida auriculata - Des Murs, 1847) is among the most common species in the Neotropics, considered both as game and pest in some countries. Here we characterized the regional and seasonal patterns of Eared Doves abundance in Southwestern Brazil and examined the relationship between landscape features and these abundance patterns. We counted Eared Doves using the point count system along routes in summer and winter and recorded land use at two scales. We used linear regressions to model the effect of landscape matrix and land use at local scale with Doves abundance in two seasons. At the landscape scale, in winter, the abundance was greater in routes crossing landscapes dominated by plantations. In summer, it was lower in routes with large tracts of forests and mixed farming. While in winter, at the local scale, the Doves abundance was greater in routes with higher frequency of maize plantations, in summer higher abundances were observed in routes with higher frequency of sugar cane and soybean plantations. Agricultural settings, which include both sustained production of food in the form of grains as well as and large stretches of habitat suitable for reproduction, favor large population of Eared Doves.

A work point count system coupled with back-propagation for solving double dummy bridge problem

The game ‘contract bridge’ is one of the most widely known card games comprising many fascinating aspects, such as bidding, playing and winning the trick including estimation of hand strength, the additional input data based on the human knowledge of the game to improve the quality of results. The game classified under a game of imperfect information is to be equally well-defined, since the decision made on any stage of the game is purely based on the decision that was made on the immediate preceding stage. The incompleteness of information, the real spirit of the card game in proceeding further deals of the game are taking into many forms especially during the distribution of cards for the next deal. One among the architectures of the Artificial Neural Network is considered by training on sample deals and used to estimate the number of tricks taken by one pair of bridge players is the key idea behind the Double Dummy Bridge Problem, implemented in this paper. The Cascade Correlation Neural Network architecture with supervised learning implemented to train data and hence to test it is coupled along with Work point count system.

A SOLUTION TO THE DOUBLE DUMMY CONTRACT BRIDGE PROBLEM INFLUENCED BY SUPERVISED LEARNING MODULE ADAPTED BY ARTIFICIAL NEURAL NETWORK

Contract Bridge is an intellectual game which motivates multiple skills and application of prior experience and knowledge, as no player knows accurately what moves other players are capable of making. The Bridge is a game played in the presence of imperfect information, yet its strategies must be well formulated, since the outcome at any intermediate stage is solely based on the choices made during the immediately preceding phase. In this paper, we train an Artificial Neural Network architecture using sample deals and use it to estimate the number of tricks to be taken by one pair of bridge players, which is the main challenge in the Double Dummy Bridge Problem. We focus on Back Propagation Neural Network Architecture with Back Propagation Algorithm with Sigmoidal transfer functions. We used two approaches namely, High - Card Point Count System and Distribution Point Method during the bidding phase of Contract Bridge. We experimented with two sigmoidal transfer functions namely, Log Sigmoid transfer function and the Hyperbolic Tangent Sigmoid function. Results reveal that the later performs better giving lower mean squared error on the output.

Evaluation of a general ecosystem state indicator based on farmland birds

The comparison analysis and assessment of certain landscapes and landscape units is an effective tool for the decision makers for meeting appropriate land use decision. In our analysis we compared various groups of indices applicable for ecological landscape assessment applying them on three lowland landscape units. The assessed indices characterize the landscape from the point of view of vegetation (vegetation-based natural capital index) and birds (diversity of birds species of agricultural areas). The vegetation-based natural capital index values have been derived from the META database collected between 2003 and 2008. The ornithological survey was carried out in the spring of 2011 by modified Danish point counting system. Our sample areas were the geographical micro-regions Csepeli- sik, Hortobagy and Nagyberek, which are landscapes dominated by agricultural lands and grasslands. The major question was whether different naturalness indicators characterize basically similar but differently used landscape areas in a similar way. We found that while a higher NCI value corresponds to a higher abundance of birds, it also corresponds to a lower diversity of bird species. This contraintuitive effect partially might be explained by the variance of the large-scale landscape structure of the assessed landscape areas.

Vulnerability mapping of groundwater contamination based on 3D lithostratigraphical models of porous aquifers

The aim of this paper is to apply a methodology in order to reconstruct a lithostratigraphic 3D model of an aquifer so as to define some parameters involved in the evaluation of the aquifer vulnerability to contamination of porous aquifers.The DRASTIC, SINTACS and AVI methods have been applied to an alluvial coastal aquifer of southern Italy. The stratigraphic reconstruction has been obtained by interpolating stratigraphic data from more than one borehole per 2km2. The lithostratigraphic reconstruction of a 3D model has been applied and used for three-dimensional or two-dimensional representations.In the first two methods, the layers of the vadose zone and the aquifer media have been evaluated not only by the interpolation of the single boreholes and piezometers, but also by the 3D model, assigning the scores of the parameters of each layer of the 3D model. The comparison between the maps constructed from the weighted values in each borehole and the maps deriving from the attribution of the values of each layer of the 3D model, highlights that the second representation avoids or minimizes the “bullseye” effect linked to the presence of boreholes with higher or lower values.The study has demonstrated that it is possible to integrate a 3D lithostratigraphic model of an aquifer in the assessment of the parameters involved in the evaluation of the aquifer vulnerability to contamination by Point Count System methods.

The Italian way to prevent groundwater contamination risk

In the early 1980's the Italian scientific community, together with a number of institutional decision-makers, realized how urgent it was to protect natural and environmental resources. They agreed that an adequate level of scientifically organized knowledge allows the accurate planning and development of environmental systems through management and direction of the actual development process, without hindering it. Since the special project was first set up in 1984, as part of the GNDCI-CNR (National Group for the Defence against Hydrogeologic Disasters, of the Italian National Council of Research) scientific context, it has been the cardinal point of Research Line 4 “Assessment of Aquifer Vulnerability”. The problem of groundwater contamination was examined in this project for the very first time in Italy in an organic and extensive manner as a key for forecasting and prevention purposes. The Italian approaches to assessing and mapping groundwater vulnerability to contamination are essentially based on two main methodologies:- The GNDCI Basic Method a HCS (Hazard Contamination Source) type approach that can be used for any type of Italian hydrogeologic situation, even where there is a limited amount of data. A unified legend and symbols are also defined for each hydrogeologic level.- The SINTACS [Soggiacenza (depth to groundwater); Infiltrazione (effective infiltration); Non saturo (unsaturated zone attenuation capacity); Tipologia della copertura (soil/overburden attenuation capacity); Acquifero (saturated zone characteristics); Conducibilità (hydraulic conductivity); Superficie topografica (Slope)] method, a PCSM (Point Count System Model) developed for use prevalently in areas with good data base coverage. The methodological approaches described in this paper now make up the Italian standard which has been set in the recent very important Italian Law (152/99) and which has now been ratified in the national guidelines produced by ANPA, the Italian National Agency for Environment Protection. In this paper the structure of the Research Line, the progress obtained by the 21 Research units (over 100 researchers) in 20 years of activity, the results gained etc. are briefly highlighted.

Applying Fuzzy logic and the point count system to select landfill sites

The treatment of solid waste is currently one of the major environmental problems facing municipalities. Thousands of tonnes of waste are generated each day, requiring a large area for disposal purposes. It is difficult to find suitable areas for the construction of such sanitary landfills as numerous criteria must be met, and landfill sites vary considerably in terms of their sophistication. The selection criteria for landfill sites should be as simple as possible, and with this in mind, we have evaluated a large number of random cases for the suitability of the site for landfill purposes using the recently advocated fuzzy approach. Using the fuzzy classification, we have attempted to develop a simple classification which uses only certain point values for available attributes. A normalized average of such attributes based on the proposed classifier is further evaluated using additionally generated random data sets. The results appear to be encouraging and indicate that the present classifier can be used as a substitute for the fuzzy-based ranking of landfill sites.

Comparison of a Commercial Weight Loss Program to Joining a Fitness Center

PURPOSE: To compare the effectiveness of a popular commercial weight loss program (CW) to joining a fitness center (FC) for weight loss and improving body composition. A secondary purpose was to investigate changes in blood chemistry and blood pressure. METHODS: Forty-three overweight (BMI ≥ 25) and sedentary women received a 12 week membership to either CW or FC. Subjects in CW were instructed to follow the dietary and exercise recommendations of the program, which generally included weekly weigh-ins, counseling sessions, and a point counting system to monitor calories. Subjects assigned to FC were instructed to follow the American College of Sports Medicine guidelines for weight loss which included both aerobic and anaerobic exercise a minimum of three times weekly. Outcomes included body weight (BW), body fat percentage (%BF) measured via skinfolds and the BOD POD, intraabdominal fat (IAF) and subcutaneous abdominal fat (SAF) measured via computed tomography, total cholesterol (TC), HDL cholesterol with subfractions, triglycerides, systolic blood pressure (SBP), and diastolic blood pressure (DBP). resULts: BW decreased significantly for CW (P <0.001) but not for FC (P = 0.055), while %BF did not change significantly for either group. SAF was significantly decreased only in the CW group. Both groups lost a significant amount of IAF and TC, SBP, and DBP decreased significantly in both groups with no between group differences. CONCLUSIONS: The purpose was to compare the real-world differences, especially changes in body composition, between joining a fitness center to joining a popular commercial weight loss program. Exercise performed in a laboratory and controlled setting typically improves body composition. The majority of exercise sessions in this study were purposely performed without supervision to mimic the real-world. Thus, the intensity and duration of exercise were ultimately subject controlled. This is a likely reason for the lack of change is %BF observed with FC. Although CW significantly reduced BW and SAF, %BF was not improved, suggesting a percentage of BW lost was in the form of lean tissue. In the long term this might be detrimental to weight loss and weight loss maintenance. Nevertheless, it appears from this research, in the short term it may be easier to comply with the recommendations of this particular commercial weight loss program and lose BW compared to joining a fitness center.

Vulnerability mapping of shallow groundwater aquifer using SINTACS model in the Jordan Valley area, Jordan

Jordan Valley is one of the important areas in Jordan that involves dense agricultural activities, which depend on groundwater resources. The groundwater is exploited from an unconfined shallow aquifer which is mainly composed of alluvial deposits. In the vicinity of the Kafrein and South Shunah, the shallow aquifer shows signs of contamination from a wide variety of non-point sources. In this study, a vulnerability map was created as a tool to determine areas where groundwater is most vulnerable to contamination. One of the most widely used groundwater vulnerability mapping methods is SINTACS, which is a point count system model for the assessment of groundwater pollution hazards. SINTACS model is an adaptation for Mediterranean conditions of the well-known DRASTIC model. The model takes into account several environmental factors: these include topography, hydrology, geology, hydrogeology, and pedology. Spatial knowledge of all these factors and their mutual relationships is needed in order to properly model aquifer vulnerability using this model. Geographic information system was used to express each of SINTACS parameters as a spatial thematic layer with a specific weight and score. The final SINTACS thematic layer (intrinsic vulnerability index) was produced by taking the summation of each score parameter multiplied by its specific weight. The resultant SINTACS vulnerability map of the study area indicates that the highest potential sites for contamination are along the area between Er Ramah and Kafrein area. To the north of the study area there is a small, circular area which shows fairly high potential. Elsewhere, very low to low SINTACS index values are observed, indicating areas of low vulnerability potential.

Malaric Placentas: A Quantitative Study and Clinico-Pathological Correlations

A histological and morphometric study was conducted on 372 placentae out of a total 440 delivered in Zanzibar. Fibrin (F), intervillous space (IVS) and Villi (V) relative volumes were determined by the point-counting system and the ratio of syncytium to blood capillaries by the linear intercept method. Parasitemia load and inflammatory reaction were graded semiquantitatively by the use of a 1 mm square grid. Parasitised red cells identified active malaria (AM), the presence of malarial pigment only identified past malaria (PM), and the absence of both characterized non-malarial placentae (NM). AM(17.87%), PM(21.61%) and NM(60.52%) placentae did not vary significantly in weight. Newborns from AM had a significantly lower weight than those from PM and NM. Peripheral and placental parasitemia were not coincident. Placental parasitemia load increased parallel with birthweight. The latter decreased with the increasing severity of the inflammation, particularly with the prevalence of lymphocytes in the IVS. Significantly increased volume of F was found in AM and PM placentae, while no significant variation was noticed in IVS and V volumes. The syncytium/capillaries ratio was significantly increased in AM. We conclude that low birthweight in malaria is linked to IVS inflammation but not to F deposits or parasitemia load. Non-leukotactic lymphokines might play some role. Morphologic aspects bespeak for a less mature placenta than expected and this might represent an adaptive change.

Geometry for characterizing fractured particle shape

In the physical model of particle formation by the catastrophic failure of a brittle solid, it is postulated that cracks sequentially form the surfaces of the fragments and that the resulting particles may be characterized by faces, edges and points. Using this simple model and several apoditic observations, three equations are derived that relate the number of points on a particle to the number of edges and faces on that particle surface. It was found that the number of points on the surface of a particle is always even, there are 50% more edges than points and the number of faces is 2 plus half the number of points. Unusual or forbidden shapes were found that are both rare and tend to disappear on further size reduction, and, moreover, are characterized by pairs of multiply connected points. Moreover, because a fragment is one of a very large number of particles, it will have traces (faces) of other particles on its surface, and its shape will be complex. Finally, using a point counting system, a particle characterization system for angular particles is proposed.