Species limits and phylogeographic structure in two genera of solitary African mole-rats Georychus and Heliophobius

African mole-rats (Bathyergidae) are an intensively studied family of subterranean rodents including three highly social and three solitary genera. Although their phylogenetic interrelations are clear, genetic diversity and the number of species within each genus is much less certain. Among the solitary genera, Heliophobius and Georychus were for a long time considered as monotypic, but molecular studies demonstrated strong phylogeographic structure within each genus and proposed that they represent complexes of cryptic species. The present study re-evaluates their internal genetic/phylogenetic structure using a combination of methodological approaches. We generated datasets of one mitochondrial and six specifically selected nuclear markers as well as of a large number of double digest restriction site associated (ddRAD) loci and then applied species delimitation analyses based on the multispecies coalescent model or clustering on co-ancestry matrices. The population structure was largely congruent across all analyses, but the methods differed in their resolution scale when determining distinct gene pools. While the multispecies coalescent model distinguished five Georychus and between eleven to thirteen Heliophobius gene pools in both Sanger sequenced and ddRAD loci, two clustering algorithms revealed significantly finer or coarser structure in ddRAD based co-ancestry matrices. Tens of clusters were distinguished by fineRADstructure and one (in Georychus) or two clusters (in Heliophobius) by Infomap. The divergence dating of the bathyergid phylogeny estimated that diversification within both genera coincided with the onset of the Pleistocene and was likely driven by repeated large-scale climatic changes. Based on this updated genetic evidence, we suggest recognizing one species of Georychus and two species of Heliophobius, corresponding to a northern and southern major lineage, separated by the Eastern Arc Mountains. Yet, the final taxonomic revision should await integrated evidence stemming from e.g.. morphological, ecological, or behavioral datasets.

The adoption of social media and social media marketing by dentists in South Africa

OBJECTIVES

The purpose of the study was to identify and understand social media usage behaviour of dentists in South Africa, in general and in particular as part of their marketing strategy and to consider the potential determinants associated with these behaviours.

METHODS

Dentists who are members of the South African Dental Association were requested to anonymously complete an online questionnaire. Apart from demographic information, respondents were asked to report on their use of social media and their adoption of social media marketing. One-on-one interviews were also conducted with three dentists, to gain a deeper understanding of their adoption of this marketing option.

RESULTS

South African dentists have started to embrace social media and 50.2% interact through these channels at least once a day. The most popular social media platforms are GooglePlus and Facebook. Respondents use social media mainly for personal purposes, including staying connected to family and friends.. Only 13.2% of those responding currently use social media as a marketing tool, but the majority (83.5%) predict that such usage will increase in future.

CONCLUSION

Social media marketing is a growing trend and will become more significant in future. Although respondents used social media regularly for personal purposes, most are only now starting to use it as a marketing tool.

Repellence of the red bud borer Resseliella oculiperda from grafted apple trees by impregnation of rubber budding strips with essential oils

The red bud borer Resseliella oculiperda (Rübs.) is a pest insect of apple trees when rootstocks are grafted with scion buds by 'shield budding'. The female midges are attracted to the wounds of the grafted buds where they lay their eggs. The larvae feed on the cambium and destroy the buds completely or partially, leading to bad union of the buds with the rootstocks. Budding strips are used very often by growers to bind scion buds to rootstocks. These strips cannot prevent midges from reaching the damaged tissue. Chemical treatments applied to the grafts and other types of strip do not provide better protection against the pest and may cause other risks for growers. In orchard experiments in 2000 and 2001, the authors evaluated the repellent action provided by three essential oils and five compounds of plant origin against the midges by impregnating budding strips with them. The essential oils of lavender, Lavandula angustifolia (P. Mill.), and alpha-terpineol decreased the infestation of buds by more than 95 and 80% respectively. The other potential repellents tested [the essential oil of Juniperus virginiana (L.), citronellal, the essential oil of Cinnamomum camphora (L.) J. Presl, R-carvone, linalool and R-fenchone] decreased infestation by 67, 66, 51, 45, 37 and 25% respectively. The formulation and commercial development of budding strips impregnated with lavender oil is discussed.

Prognostic value of day 14 blast percentage and the absolute blast index in bone marrow of children with acute lymphoblastic leukemia

The product of the percentage blasts on the bone marrow aspirate (BMA) and the biopsy cellularity has been termed the "absolute blast index aspirate" (ABI-aspirate) and is used to measure disease response on day 7 of induction therapy. The authors compared the event-free survival (EFS) in high-risk and standard-risk patients as identified by the ABI-aspirate and the BMA percentage blasts on day 14 of induction therapy. Both indices identified high-risk cases. EFS of patients categorized as high-risk by these 2 methods and the high-risk criteria used by the authors' service (WCC of > 20 x 10(9)/L, age < 2 and > 8 years and a peripheral blood blast count of > 1.0 x 10(9)/L on day 8 of induction) did not differ. There was concordance between patients identified as high risk by all 3 methods. The results confirmed the prognostic value of the ABI-aspirate and the BMA percentage blasts on day 14 of induction therapy, but these methods were not superior to the high-risk criteria currently in use.

Continuity of psychopathology in youths referred to mental health services

OBJECTIVE

To investigate the stability and predictive strength of behavioral and emotional problems in childhood and adolescence.

METHOD

A referred sample (N = 1,652), aged 4 to 18 years at initial assessment, was followed up after a mean interval of 6.2 years. Problem scores derived from Child Behavior Checklist, Youth Self-Report, and Teacher's Report Form at initial assessment (T1) were related to scores on the same instruments at follow-up (T2).

RESULTS

Correlations between T1 and corresponding T2 problem scores averaged 0.41 intrainformant (range 0.22-0.61) and 0.22 interinformant (range -0.09-0.57). Stabilities were similar across gender, and larger for Externalizing versus Internalizing scores, except on youths' self-reports. Psychopathology scores at follow-up were predicted by corresponding T1 scores. Girls were predicted to have higher T2 Somatic Complaints, Anxious/Depressed, Thought Problems, and Internalizing scores than boys. Children younger at intake were predicted to have higher scores than older children on T2 Social and Attention Problems.

CONCLUSIONS

Findings indicate continuity of specific behavioral and emotional problems in clinically referred children and adolescents.

Condom use by Dutch men with commercial heterosexual contacts: determinants and considerations

We report responses from 559 clients of female prostitutes, with a view to determining to what extent previously identified factors play a part in condom use. To increase the response rate to advertisements in daily and weekly newspapers, interviews were held by phone. This procedure had the advantage of ensuring the anonymity many clients demanded. Of those clients having vaginal or anal contact (91%), 14% had not always used condoms in the previous year. Compared with consistent condom users, these men were less highly educated, had twice as many commercial contacts, and had more contacts with "steady" prostitutes. They were either more emotionally motivated to visit prostitutes than were consistent condom users or exhibited a stronger need for sexual variation. They showed a more compulsive attitude toward visiting prostitutes, had a more negative attitude toward prostitution in general, evaluated condoms more negatively, had a higher personal efficacy to achieve unsafe contacts, and had a higher general risk assessment, commensurate with their behavior. Men with only safe contacts had either an intrinsic or an extrinsic motivation for condom use. Among extrinsically motivated men, their behavior change was more recent and had not yet taken root: They still envisioned unsafe commercial sex to be possible in the future. Education aimed at the small group of men practicing unsafe contacts will not easily and directly lead to behavior change. But these educational activities may support prostitutes to persist in (consistent) condom use, regardless of clients' pressure to do otherwise.

Segmentation of heterosexual prostitution into various forms: a barrier to the potential transmission of HIV

The results of an earlier Dutch study on prostitutes' clients, interviewed face-to-face, were cross-validated by means of telephone interviews, which both guaranteed anonymity and produced a larger sample of respondents (n = 559). Depending on their preference and financial resources, they had visited different types of prostitution; but about half of them had restricted themselves to one type. Inconsistent use of condoms was reported by 14% of the clients who had had vaginal or anal intercourse. Condoms were most frequently used in clubs, brothels and window prostitution, and least often in street, home and escort prostitution; in the last two sorts especially not with regular prostitutes. Whether or not prostitutes came from non-Western countries had no influence on protective behaviour of these clients. The formation of networks between different sorts of prostitution, through unsafe sexual contacts in two or more sorts, involved only 3% of respondents. Thus, prostitution in The Netherlands should be seen as a number of sparsely-connected networks rather than as a single network. The formation of networks between prostitution and the population at large is made possible by the 10% of the respondents who had had unsafe contacts with both commercial and private partners.

Isolation and characterization of a microspore-specific gene from tobacco

The characterization of a gene with a unique microspore-specific expression pattern is reported. Isolated microspores from tobacco were used to synthesize a cDNA library. Clones that did not hybridize to leaf cDNA were further characterized by northern analysis. One clone proved to be a microspore-specific cDNA, representing a transcript of 650 nt. The corresponding gene, NTM19 (Nicotiana tabacum microspore-specific), was isolated and its sequence analysed. The gene encodes a protein of 10.8 kDa with a pI of 6.92 and a putative signal sequence at the N-terminus. A localization study revealed a unique spatial and temporal distribution. The transcript was only detected in the unicellular microspore. No hybridization signals were observed in other pollen developmental stages, nor in the surrounding anther tissues or other vegetative tissues of the plant. Therefore it can be concluded that NTM19 is a gene with a highly microspore-specific character according to both localization and stage of expression. Southern blot analysis demonstrated the presence of a small gene family. The occurrence of TNM19 was investigated in a range of closely and distantly related species and was found to be present in other solanaceous species, including the ancestors of tobacco and in a monocot species.

Luteinizing hormone, follicle-stimulating hormone, testosterone and dihydrotestosterone during testicular descent in the pig fetus

To investigate the relationship between gonadotrophins, androgens and testicular descent in the pig fetus, serum concentrations of luteinizing hormone (LH) and follicle-stimulating hormone (FSH), and serum concentrations and testicular content of testosterone (T) and 5 alpha-dihydrotestosterone (DHT) were determined by radioimmunoassay in 95 fetuses (48 males, 47 females) between Day 60 and Day 90 post coitum (p.c.). The testes were descended in 0% of fetuses at Day 60, 8% of fetuses at Day 70, 40% of fetuses at Day 80 and 87% of fetuses at Day 90 p.c. There was a significant increase in mean serum concentrations of LH in both male and female fetuses from Day 60 to Day 90, with a significant difference in mean serum concentrations of LH between male fetuses with a body mass < 350 g (4% of testes descended) and those with a body mass > 450 g (87% of testes descended), but not between male and female fetuses < 350 g or > 450 g in body mass. There was no significant difference in mean serum concentrations of FSH between male and female fetuses. Mean serum concentrations of T were significantly higher in male fetuses at Day 60 than in those at Days 70-90, with no significant difference in serum concentrations of DHT from Day 60 to Day 90 p.c. Testicular content of T and DHT showed a non-linear increase from Day 60 to Day 90 p.c. Although the serum concentration of T is elevated before, and decreased during, the period of descent, the testicular content of T and DHT increases during the period of descent, indicating that serum concentrations of LH and FSH may have an indirect effect on descent by stimulating testicular androgen synthesis.

Professional HIV risk taking, levels of victimization, and well-being in female prostitutes in The Netherlands

Professional HIV risk taking (nonconsistent condom use with clients) of female prostitutes in The Netherlands is addressed within the context of (early) experiences with abuse, well-being, coping behavior, job satisfaction, and financial need. Data were gathered from 127 female prostitutes on condom use, financial need, and professional attitude, and on experiences with violence and abuse, physical complaints, psychosocial problems, and coping responses. Violent traumatic experiences were found to relate to more severe complaints and problems, and a higher frequency of emotion-focused coping strategies. A risk-taking protection style (as opposed to consistent condom use and selective risk taking) appeared to be associated with more severe experiences with violence, both in childhood and in adult life, with more frequent dissociation as a coping behavior, and with more psychosomatic complaints. Of all the relationships found, more severe experiences with violence on the job were most strongly related to a higher professional HIV risk.

Alcohol and drug use in heterosexual and homosexual prostitution, and its relation to protection behaviour

To assess the prevalence and effects of alcohol and drug use in heterosexual and homosexual commercial contacts, and the relationship between their use and unsafe sexual behaviour, 127 female prostitutes, 27 male prostitutes, 91 clients of female prostitutes and 24 clients of male prostitutes were interviewed face-to-face with the help of a semi-structured questionnaire. The respondents were living or working in different parts of The Netherlands. Alcohol and drug use was found to be relatively common among prostitutes. This was also so for the use of alcohol by clients, though to a lesser extent. Prostitutes' consumption varied widely according to the type of prostitution they were employed in. Those meeting their clients in clubs or bars reported the highest consumption of alcohol; hard drugs were used predominantly by street prostitutes. It appears that the main effects of alcohol and drug use are on how the individual experiences working as, or calling on, a prostitute, the social interaction between the two parties, and the sexual contact itself. The common assumption that drinking alcohol has negative effects on condom use was not borne out; though female prostitutes working under the influence of drugs were significantly more likely to report unsafe sex. The degree to which commercial partners were judged to be under the influence of alcohol or drugs was not found to bear upon the frequency of respondents' condom use. For those prostitutes who use hard drugs, this use plays an important role in their engaging in unsafe sexual activities. Prevention activities should focus especially on this group, and should take into account the role of such drug use.

Proliferation of gubernaculum cells induced by a substance of low molecular mass obtained from fetal pig testes

To investigate the hormonal control of gubernacular development and testicular descent we determined the effect of gonadal extracts and various hormones on the proliferation of gubernaculum cell cultures established from 55 male pig fetuses obtained at 60 to 90 days' gestation. The percentage of descended testes was 0 at 60, 8% at 70, 40% at 80 and 87% at 90 days' gestation. Significant proliferation (as measured by [3H]thymidine incorporation) of gubernaculum, but not 3T3, cells was induced by crude testicular but not ovarian extracts, and was directly related to its protein concentration. Significant proliferation of gubernaculum cells was induced by low molecular mass (< 30 kD) testicular, but not by high molecular mass (> 30 kD), testicular and low or high molecular mass ovarian extracts obtained by centrifugation of crude extracts in microspin filter membranes with a molecular cut-off mass of 30 kD. Proliferation of gubernaculum cells induced by the low molecular mass (<30 kD) testicular extract was significantly greater than that stimulated by testosterone or dihydrotestosterone. Polyacrylamide gel electrophoresis demonstrated a unique protein band at approximately 26 kD in the crude and low molecular mass testicular, but not in the ovarian, extracts. It is possible that this represents a novel peptide hormone secreted by the fetal testis, responsible for stimulating the growth of the gubernaculum, thereby mediating testicular descent.

Male prostitutes and safe sex: different settings, different risks

Twenty-seven male prostitutes were interviewed extensively about their work and considerations relating to safe sex with clients. Important differences were found between street prostitutes and those working at home. Street-workers were more likely to be using hard drugs, to have a heterosexual preference, to have no other occupation, to have more clients, but less steady ones, and to have a more negative working attitude. Sexual techniques most often practised were manual and oral contact; however, most prostitutes also practised either insertive or receptive anal intercourse. Homosexual male prostitutes reported more receptive anal intercourse than did their heterosexual male colleagues; but no such differences were found in insertive anal intercourse. Prostitutes were most likely to have had anal intercourse with steady clients, with clients whom they trusted regarding condom use, or with clients they felt sexually attracted to; and also when in dire need of drugs. Of those who had practised anal intercourse in the previous year, a minority had not consistently used condoms. The same factors that encourage anal intercourse also appear conducive to unprotected intercourse.

The effectiveness of condom use in heterosexual prostitution in The Netherlands

OBJECTIVES

To assess the extent to which condoms are used effectively in commercial heterosexual intercourse. Data on the number of condoms that had broken or slipped off, the sexual technique during which this had occurred and the perceived cause of failure were collected. The use of non-water-soluble lubricants and non-fortified condoms during anal intercourse, and the demand for a greater variety of condom sizes were also examined.

SUBJECTS AND METHODS

One hundred and twenty-seven female prostitutes and 91 male clients from different parts of The Netherlands were interviewed face-to-face between July 1990 and March 1991.

RESULTS

Of those who used condoms during vaginal intercourse, 49% of the prostitutes had experienced condom breakage in the previous 6 months, and 16% of the clients in the previous 12 months. The breakage rate was 0.8% for prostitutes and 1.5% for clients. Condom quality was seldom reported as the cause; breakage was generally attributed to human factors, such as rough or prolonged intercourse, incorrect handling of the condom or the use of insufficient lubricant. Prostitutes also identified penis size as a cause. Condoms slipping off before or after ejaculation was reported less frequently than breakage. Thirteen per cent of clients and 36% of prostitutes expressed a need for either smaller or larger condoms. Of the prostitutes, 9% used oil or vaseline as a lubricant.

CONCLUSIONS

In view of the low rate of condom failure in heterosexual prostitution in The Netherlands, the potential spread of HIV by this means is small. The use of a greater variety of condom sizes may further reduce the failure rate. Few prostitutes remain ignorant about the adverse effects of oil-based lubricants on condoms.

Construction of behaviourally anchored rating scales (BARS) for the measurement of managerial performance

BARS were initially developed as indices of behavioural change and to ensure greater comparability of ratings from different raters. In this study, BARS were developed for a major producer-wholesaler company in the liquor industry to serve as an independent criterion in the validation of the company's assessment center, to assess the impact of development activities on the skill levels of assessment centre participants and as a diagnostic tool in identifying performance deficiencies. A step-by-step account of the four stages in the development of BARS is presented, together with examples of actual scales for the final steps. Opsomming Gedragsgeankerde skale (BARS) is oorspronklik ontwikkel as indekse van verandering, en om die vergelykbaarheid tussen beroordelings van verskillende beoordelaars te verhoog. In hierdie studie is BARS vir 'n groothandelaar in die drankbedryf ontwikkel ten einde te dien as 'n onafhanklike kriterium in die validering van hulle takseersentrum; om die invloed van ontwikkelingsaktiwiteite op die vaardigheidsvlakke van deelnemers aan die takseersentrum te meet; en as 'n diagnostiese hulpmiddel in die indentifisering van ontoereikende prestasie. 'n Stap-vir-stap beskrywing van die vier stadia in die ontwikkeling van BARS word gegee, met voorbeelde van werklike skale vir die finale stappe.

Validation of an assessment centre against bars: An experience with performance related criteria

The objective of this study is to determine the validity of a middle management assessment centre. Behaviourally Anchored Rating Scales were developed specifically for this purpose. The results testify to the validity of this assessment centre and lend support to the argument that assessment centres do indeed predict performance criteria (viz a viz potential/advancement criteria). The validity coefficients for the various dimensions are indicated. Opsomming Die doel van hierdie studie is om die geldigheid van 'n takseersentrum vir middelbestuur te bepaal. Vir die doel is gedragsgeankerde skale as kriterium spesiaal ontwikkel. Die resultate dui op die geldigheid van hierdie takseersentrum en verleen addisionele steun aan die argument dat takseersentrums wel prestasiekriteria (viz a viz potensiaal/bevorderingskriteria) voorspel. Die geldigheidskoeffisiente van die onderskeie bestuursdimensies word aangetoon.

The venom of Ampulex compressa--effects on behaviour and synaptic transmission of cockroaches

1. The solitary wasp Ampulex compressa stings a cockroach, Periplaneta americana, twice. 2. The first sting into the ventral thorax results in a transient paralysis. During this paralysis the wasp stings the suboesophageal ganglion, which gradually results in a permanent deactivation. 3. The venom gland is a paired and highly branched organ, with a common ductus venatus. The large lumen is lined with a folded cuticula. No venom reservoir is present. 4. Extract of the venom gland induces a slow contraction of the guinea pig ileum. 5. The agonist present in the venom cannot be identified with a known agonist. 6. Venom gland extract blocks synaptic transmission from the cercal nerve to giant neurons in the sixth abdominal ganglion of the cockroach. 7. The block develops gradually, like the gradual appearance of the effects of the sting into the suboesophageal ganglion on the behaviour of the cockroach.

Specificity-related suppression of responses to binary mixtures in olfactory receptors of the Colorado potato beetle

Responses of antennal olfactory receptors of the Colorado potato beetle (Leptinotarsa decemlineata Say) to stimulation with 5 general green odour components, i.e. cis-3-hexen-1-ol, trans-2-hexenal, cis-3-hexenyl acetate, trans-2-hexen-1-ol and 1-hexanol, were recorded extracellularly. Response spectra derived from these recordings cannot be classified into distinct reaction types. The spectra overlap in their sensitivity to individual stimuli, but there are differences in their degree of specialization with a gradual conversion from generalist to specialist receptors. Moreover, specialization is found to different stimuli. Receptor reactions to stimulation with binary mixtures of 3 of these compounds indicated that suppression of the response to one chemical by another is very common in olfactory receptor cells. The more a receptor is specialized, the stronger is this suppression. Suppression in narrowly tuned olfactory receptor neurones, therefore, is expected to play a fundamental role in the recognition of natural odour blends.

Integration of olfactory information in the Colorado potato beetle brain

The processing of olfactory information in the Colorado potato beetle, Leptinotarsa decemlineata Say, was studied by recording responses of olfactory neurones intracellularly in the deutocerebrum. Response characteristics of neurones in this first relay station of the olfactory pathway were measured when the antennae were stimulated with five general green leaf volatiles, i.e. cis-3-hexen-1-ol, trans-2-hexenal, cis-3-hexenyl acetate, trans-2-hexen-1-ol and 1-hexanol. These compounds are part of the so-called green odour of potato, whose defined composition is essential for the beetle's host plant finding. The response spectra of deutocerebral neurones can be divided roughly into two classes: one class containing neurones which are not very specific for the tested compounds, and another class with highly specialized neurones. Their different responses to a potato leaf extract suggest two channels for the processing of olfactory information in the antennal lobe: one channel for the detection of the presence of green leaf odour components, and another one for an evaluation of the component ratios.

Tydorientasie versus Diepte-orientasie as dimensies van die 4-D teorie

The relationship between two of the dimensions of the 4-D theory (Raubenheimer, 1978), namely the time dimension (Augustyn, 1978) and the depth dimension (De Jager, 1979) has been investigated. The hypothesis that there is no correlation between an individual's time orientation and his depth orientation, is substantiated by the data. The possible influence of pre-selection factors on the results, however, cannot be ignored.

Beeldebevordering as 'n promosiestrategie en uitvloeisel van sosiaal-verantwoordelike handelinge - 'n studie in die wynbedryf

A survey of the literature indicates that certain economic requirements have to be met should business firms make use of image building as a means of promoting their products. Seven hypotheses about the way in which consumers associate firms with their products in the wine industry are formulated and tested on a sample of 220 students. A skewed distribution of the knowledge of the origin of wines is reported. Furthermore, a significantly greater number of students could specify the trademarks of one of the firms, because this firm more explicitly associates with its products. Results indicate a need for reassessing the economic benefits reaped from image building in the wine industry.Opsomming'n Oorsig van die literatuur dui daarop dat sakeondernemings wat van beeldbevordering as 'n promosiestrategie gebruik maak, sekere vereistes moet nakom ten einde die potensiële ekonomiese voordele te kan realiseer. Sewe hipoteses oor die koppeling tussen maatskappy en produk in terme van verbruikers se hoeveelheid kennis ten opsigte van die herkoms van wynprodukte, is geformuleer en getoets. 'n Monster van 220 studente is in die ondersoek gebruik en daar is gevind dat kennis ten opsigte van die herkoms van wyne nie-normaal versprei is. Beduidend meer studente kon die handelsmerke van een van die maatskappye korrek spesifiseer, aangesien hierdie maatskappy 'n koppeling tussen sy naam en produkte in 'n groter mate moontlik maak. Die verkreë resultate dui op die noodsaaklikheid van 'n herwaardering van die realiseerbaarheid van ekonomiese voordele van beeldbevordering deur middel van sosiaal-verantwoordelike handelinge.

Morphological observations on leaf haustoria and related organs of the South African genus Hyobanche (Scrophulariaceae)

Most haustoria in Hyobanche (Scrophulariaceae) are formed directly from the scale leaves of the extensive rhizome system and may be found on adaxial surfaces, margins, or tips of such leafy organs. The only exceptions are occasional haustoria, emerging from rhizome areas between adjacent scale leaves, and the primary haustorium. Host roots appear to be attracted to the rhizome, growing along its surface and apparently eliciting haustorial formation in adjoining parasitic tissues. The established parasite is completely rootless.