Phase Pattern Formation in Grain Boundaries.

In this Letter we derive conditions that predict the existence of two-phase periodic-pattern grain boundary structures that are stable against coarsening. While previous research has established that elastic effects can lead to phase pattern formation on crystal surfaces, the possibility of stable grain boundary structures composed of alternating grain boundary phases has not been previously analyzed. Our theory identifies the specific combination of grain boundary and materials properties that enable the emergence of patterned grain boundary states and shows that the dislocation content of grain boundary phase junctions, absent in surface phenomena, weakens the stability of the patterned structures. The predictions of the theory are tested using a model copper grain boundary that exhibits multiple phases and two-phase pattern formation. We discuss how, similarly to surfaces, elastic effects associated with grain boundary phase junctions have profound implications for how grain boundary phases transform.

Nucleation of Grain Boundary Phases.

We derive a theory that describes homogeneous nucleation of grain boundary (GB) phases. Our analysis takes account of the energy resulting from the GB phase junction, the line defect separating two different GB structures, which is necessarily a dislocation as well as an elastic line force due to the jump in GB stresses. The theory provides analytic forms for the elastic interactions and the core energy of the GB phase junction that, along with the change in GB energy, determines the nucleation barrier. We apply the resulting nucleation model to simulations of GB phase transformations in tungsten. Our theory explains why under certain conditions GBs cannot spontaneously change their structure even to a lower energy state.

No need to beat around the bushmeat-The role of wildlife trade and conservation initiatives in the emergence of zoonotic diseases.

Wildlife species constitute a vast and uncharted reservoir of zoonotic pathogens that can pose a severe threat to global human health. Zoonoses have become increasingly impactful over the past decades, and the expanding trade in wildlife is unarguably among the most significant risk factors for their emergence. Despite several warnings from the academic community about the spillover risks associated with wildlife trade, the ongoing COVID-19 pandemic underlines that current policies on the wildlife industry are deficient. Conservation initiatives, rather than practices that attempt to eradicate zoonotic pathogens or the wild species that harbour them, could play a vital role in preventing the emergence of life-threatening zoonoses. This review explores how wildlife conservation initiatives could effectively reduce the risk of new zoonotic diseases emerging from the wildlife trade by integrating existing literature on zoonotic diseases and risk factors associated with wildlife trade. Conservation should mainly aim at reducing human-wildlife interactions in the wildlife trade by protecting wildlife habitats and providing local communities with alternative protein sources. In addition, conservation should focus on regulating the legal wildlife trade and education about disease transfer and safer hunting and butchering methods. By uniting efforts for wildlife protection and universal concern for preventing zoonotic epidemics, conservation initiatives have the potential to safeguard both biodiversity, animal welfare, and global human health security.

[Frontal lobe epilepsy or a psychogenic disorder? The importance of taking a good patient history]. / Frontale epilepsie of een psychogene aandoening?

BACKGROUND: Frontal lobe epilepsy (FE) is a diagnosis which can be easily missed due to the variety in symptoms. The symptoms depend on the location of the epileptical activity in the frontal lobe. CASE DESCRIPTION: A 48-year-old man of Moroccan descent is diagnosed with frontal epilepsy, but this diagnosis is rejected based on the 24-hours EEG. Instead he is diagnosed with psychogenic non-epileptic seizures (PNES). Upon this diagnosis, he develops reactive depressive symptoms and he is referred to the psychiatrist. However, based on the clinical presentation the diagnosis PNES is overruled and replaced with frontal lobe epilepsy. The patient recovers when he is treated with valproic acid. CONCLUSION: The article describes the symptoms of FE and those of PNES. This case description demonstrates the difficulties and illustrates the importance of a good history when diagnosing FE.

Effects of seasonality and previous logging on faecal helminth-microbiota associations in wild lemurs.

Gastrointestinal helminth-microbiota associations are shaped by various ecological processes. The effect of the ecological context of the host on the bacterial microbiome and gastrointestinal helminth parasites has been tested in a number of ecosystems and experimentally. This study takes the important step to look at these two groups at the same time and to start to examine how these communities interact in a changing host environment. Fresh faecal samples (N = 335) from eight wild Eulemur populations were collected over 2 years across Madagascar. We used 16S ribosomal RNA gene sequencing to characterise the bacterial microbiota composition, and faecal flotation to isolate and morphologically identify nematode eggs. Infections with nematodes of the genera Callistoura and Lemuricola occurred in all lemur populations. Seasonality significantly contributed to the observed variation in microbiota composition, especially in the dry deciduous forest. Microbial richness and Lemuricola spp. infection prevalence were highest in a previously intensely logged site, whereas Callistoura spp. showed no such pattern. In addition, we observed significant correlations between gastrointestinal parasites and bacterial microbiota composition in these lemurs, with 0.4-0.7% of the variation in faecal bacterial microbiota composition being explained by helminth infections. With this study, we show effects of environmental conditions on gastrointestinal nematodes and bacterial interactions in wild lemurs and believe it is essential to consider the potential role of microbiome-parasite associations on the hosts' GI stability, health, and survival.

The agony of choice in dermatophyte diagnostics-performance of different molecular tests and culture in the detection of Trichophyton rubrum and Trichophyton interdigitale.

Dermatophytosis caused by dermatophytes of the genera Trichophyton and Microsporum belong to the most frequent mycoses worldwide. Molecular detection methods proved to be highly sensitive and enable rapid and accurate detection of dermatophyte species from clinical specimens. For the first time, we compare the performance of different molecular methods with each other and with conventional diagnostics in the detection of dermatophytoses caused by Trichophyton rubrum and Trichophyton interdigitale in clinical specimens (nail, skin and hair). The compared molecular methods comprise two already published PCR-ELISAs, a published quantitative RT-PCR as well as a newly developed PCR-ELISA targeting the internal transcribed spacer region. We investigated the sensitivity of the assays by analysing 375 clinical samples. In 148 specimens (39.5%) a positive result was gained in at least one of the four molecular tests or by culture, but the number of detected agents differed significantly between some of the assays. The most sensitive assay, a PCR-ELISA targeting a microsatellite region, detected 81 T. rubrum infections followed by an internal transcribed spacer PCR-ELISA (60), quantitative RT-PCR (52) and a topoisomerase II PCR-ELISA (51), whereas cultivation resulted in T. rubrum identification in 37 samples. The pros and cons of all four tests in routine diagnostics are discussed.

Response to best-frequency tone bursts in the ventral cochlear nucleus is governed by ordered inter-spike interval statistics.

The spike trains generated by short constant-amplitude constant-frequency tone bursts in the ventral cochlear nucleus of the anaesthetised guinea pig are examined. Spikes are grouped according to the order in which they occur following the onset of the stimulus. It is found that successive inter-spike intervals have low statistical dependence according to information-theoretic measures. This is in contrast to previous observations with long-duration tone bursts in the cat dorsal and posteroventral cochlear nuclei and lateral superior olive, where it was found that long intervals tended to be followed by shorter ones and vice versa. The interval distributions can also be reasonably modelled by a shifted Gamma distribution parameterised by the dead-time and the mean and coefficient of variation of the dead-time corrected ISI distribution. Knowledge of those three parameters for each interval is sufficient to determine the peri-stimulus time histogram and the regularity measures used to classify these neurons.

[Trichophyton thuringiense H.A. Koch 1969. A rare geophilic dermatophyte--now isolated for the first time from man]. / Trichophyton thuringiense H.A. Koch 1969. Ein seltener geophiler Dermatophyt, erstmals vom Menschen isoliert.

BACKGROUND: In 1969, Kolipp and Hoffmann isolated Trichophyton (T.) thuringiense spec. nov. Koch when they performed their thesis dealing with the distribution and epidemiology of dermatophytes and keratinophilic fungi in mice and other small mammals. At that time, T. thuringiense was detected as saprophytic fungus of the skin of different mice species (e.g. Mus musculus) both in rural and urban settings in the area of Thuringia in Germany. There were no further reports on this dermatophyte species until now, neither in animals, nor in man. PATIENT, METHODS AND RESULTS: Currently, we were able to isolate this geophilic fungus for the first time from a human being. A 58 year old patient baker by trade and living in a rural setting (village) suffered from nail changes like hyperkeratosis and thickening of the nail plate of his big toe. From his nail samples grew a dermatophyte with peripheral radiating and flat colonies which were a bit cottony in the centre. On Sabouraud's 4 % dextrose agar the thallus of the fungus was white to purple stained, the reverse side showed a dark red to brown color. In a typical manner, macroconidia were cylindrical to clavate, microconidia obovoidal to short-clavate with broad base. The species identification of T. thuringiense was done and confirmed by sequence analysis of the internal transcribed spacer (ITS) region of the ribosomal DNA. Antifungal treatment has been refused from the patient. CONCLUSION: In conclusion, this is the second description of the geophilic dermatophyte T. thuringiense, which could be isolated for the first time from a human being, in particular from nail sample of the big toe under the suspicion of onychomycosis. However, it is still uncertain if this fungus should be considered either as secondary colonization of the nail plate, or as causative agent of tinea unguium or onychomycosis.

[Molecular biological detection of dermatophytes in clinical samples when onychomycosis or tinea pedis is suspected. A prospective study comparing conventional dermatomycological diagnostics and polymerase chain reaction]. / Molekularbiologischer Direktnachweis von Dermatophyten im klinischen Material bei Verdacht auf Onychomykose und Tinea pedis. Eine prospektive Studie zum Vergleich konventioneller dermatomykologischer Diagnostik und der Polymerasekettenreaktion.

BACKGROUND: The prevalence of onychomycosis is rising worldwide. Before starting antifungal treatment, an exact mycological diagnosis should be obtained. The current laboratory diagnosis of dermatomycoses is based on the detection of the causative agent by microscopy and culture. These conventional diagnostic methods for fungal infections often are not the best solution because they are time-consuming, cultures are false-negative and direct examination identifies non-vital structures which cannot be used for speciation. PATIENTS AND METHODS: A total of 218 patients presenting in a surgical practice over 3 months with clinical signs of tinea pedis and/or onychomycosis were involved in the prospective study. All patients had predisposing factors for tinea pedis and tinea unguium, such as vascular insufficiency, diabetes mellitus, and leg ulcers. Nail specimens and skin scrapings were investigated for fungi using Blancophor® preparation, and cultured. In addition to conventional diagnostics, PCR (polymerase chain reaction) for detection of dermatophyte DNA was employed. This PCR-Elisa assay is based on the use of specific primers which target the topoisomerase II gene. This allows the highly specific molecular identification of Trichophyton (T.) rubrum, T. interdigitale, and Epidermophyton floccosum directly in clinical samples. RESULTS: 23.9 % of patients were culture-positive for dermatophytes (either T. rubrum, or T. interdigitale). With PCR, dermatophyte DNA either of T. rubrum or T. interdigitale could be detected in nail samples and skin scrapings from at least 29.9 % of all patients. Epidermophyton floccosum was not found in this study, neither by cultivation nor by PCR. The diagnostic sensitivity of the PCR-Elisa assay was calculated as 79.0% ; the diagnostic specificity as 85.5 %. CONCLUSION: PCR-Elisa evaluation makes possible a rapid, specific and sensitive diagnosis of dermatophytosis of the nails and skin within 24 (maximal 48) hours with identification of the involved species.

Development of a novel polymerase chain reaction-enzyme-linked immunosorbent assay for the diagnosis of Trichophyton rubrum onychomycosis.

BACKGROUND: The prevalence of onychomycosis has increased steadily in the past decade. An accurate diagnosis at the outset is important for successful and cost-effective treatment of patients. However, current diagnostic tests for onychomycosis are not rapid, sensitive or specific. OBJECTIVES: To develop a microsatellite-based polymerase chain reaction (PCR)-enzyme-linked immunosorbent assay (MS-ELISA) for the detection of Trichophyton rubrum, which is the most common aetiological agent of onychomycosis. METHODS: An archival set of 434 nail and skin specimens from 217 patients was included as the test sample in this study. We also compared MS-ELISA with an earlier published topoisomerase PCR-ELISA (TI-ELISA) using template DNA extracted by another method. RESULTS: The MS-ELISA detected the highest number of positive samples (69%) followed by direct microscopy (56%), TI-ELISA (44%) and fungal culture (30%). When an identical DNA extraction method was applied to 120 specimens, the MS-ELISA proved to be twice as sensitive as the TI-ELISA. CONCLUSIONS: We have optimized a target gene and DNA extraction method for rapid detection of T. rubrum onychomycosis.

An exact method of regularity analysis for auditory brainstem neurons (L).

The standard regularity analysis for spike trains in cochlear nucleus neurons evoked by tonebursts first proposed by Bourk is widely used, primarily as one of the criteria for classification of such neurons. It is shown that this procedure does not estimate quite what it is supposed to, and introduces unnecessary noise to its results due to its use of bins. Instead the desired quantities (mean and coefficient of variation of the lengths of all inter-spike intervals in progress as a function of time since stimulus onset) can all be exactly calculated directly from the spike train without the need for data binning. The implications for classification and other studies are discussed.

Wound infection after cataract surgery: a report of two cases.

BACKGROUND: This is a report of 2 cases of fungal wound infection after cataract surgery (phacoemulsification). Both patients were noticed to have the fungal wound infection at the one-month follow-up after the surgery. OBSERVATIONS: Although both patients had been advised to taper steroid containing antibiotic eye drops, they failed to do so. Despite intensive treatment with antifungal eye drops and oral antifungal agents, visual outcome was poor. CONCLUSION: Fungal infection of the wound may occur in cataract patients in the post-operative period. This infection is probably more common in patients who have had a temporal incision and who are from an agricultural background living in a hot and humid climate.

Phacoemulsification versus small incision cataract surgery (SICS): which one is a better surgical option for immature cataract in developing countries?

BACKGROUND: several studies have shown comparable visual outcomes of SICS and phacoemulsification (Gogate et al 2007, Ruit et al 2007). OBJECTIVE: to compare the safety and efficacy of different types of surgical procedures (phacoemulsification versus SICS) for cataract surgery in immature cataract. MATERIAL AND METHODS: a prospective randomized controlled trial was carried out involving 93 and 89 patients with immature senile cataract selected for phacoemulsification and SICS respectively. STATISTICS: mean values with standard deviations were calculated. P value of less than 0.05 was considered significant. RESULTS: there was no difference between the groups in terms of gender, age and pre-operative visual acuity (p = 0.09). In phacoemulsification group (n=93) more than two thirds and in SICS group (n=89) more than three quarters of the patients had good visual outcome (6/6-6/18) on first postoperative day (p=0.065). Poor outcome (<6/60) was recorded in 6% (phacoemulsification group) and 1% (small incision cataract surgery group). Mean visual acuity was 0.43 +/- 0.27 in phacoemulsification group and 0.47 +/- 0.24 in SICS group. Mean surgery time was significantly shorter in SICS group (p=0.0003). STATISTICS: data were computed and analyzed using the SPSS software program vs 10. The p value of < 0.05 was considered significant. CONCLUSION: there was no significant difference in visual outcome on first post operative day in between phacoemulsification and SICS technique. However, performing SICS was significantly faster. Small incision cataract surgery with implantation of rigid PMMA lens is a suitable surgical technique to treat immature cataract in developing countries.

Management of intra-vitreal cysticercosis.

BACKGROUND: south east Asia is an endemic zone for cysticercosis. Oocular cysticercosis is emerging as a common problem which if untreated can lead to severe visual loss in 3-5 years. CASES: we describe here a case series of three patients with intravitreal cysticercosis and managed by surgical cyst removal by pars plana vitrectomy. OBSERVATION: the procedure was successful in all cases to maintain anatomical integrity of the globe with some functional gain of vision. CONCLUSION: surgical intervention in ocular intravitreal cysticercosis is an acceptable approach with good results.

Loupe magnification for small incision cataract surgery--an alternative to microscope magnification?

A Prospective randomized controlled study was conducted to compare outcome of Small Incision Cataract Surgery (SICS) using microscope or loupe magnification. Two hundred fifty one patient with mature cataract were randomly allocated to SICS-Fishhook Technique with either microscope (127 eyes) or loupe (124 eyes) magnification. Intra- and postoperative complications and immediate visual outcome were analyzed. Nearly two third (microscope 65% and magnifying loupe 62.9%) of all patients had good visual outcome on first postoperative day. Poor outcome (<6/60) was recorded in 8% (microscope group) and 7% (magnifying loupe group). Mean visual acuity with Snellen was 0.39 (SD 0.2) in microscope group and 0.38 (SD 0.2) in magnifying loupe group. Intra operative complications were comparable in both groups. Mean surgery time with loupe magnification was significantly shorter. Comparatively equivalent good surgical outcome was achieved with loupe as well as with microscope magnification. However performing SICS with loupe magnification is significantly faster. Small incision cataract surgery with loupe magnification is safe and effective procedure for cataract surgery so it can play a role in reducing cataract blindness in developing countries of the world.

Explantation of damaged foldable acrylic lens with implantation of foldable intraocular lens without enlarging incision.

Phacoemulsification with foldable intraocular lens (IOL) implantation has several advantages because of smaller incision and sutureless technique. The visual recovery is usually fast and any surgically induced astigmatism can be kept at lowest. With increased number of trained phacosurgeons in Nepal, more phacosurgeries with foldable lens implantation are being done. Main purpose of this article is to share our experience with ophthalmic surgeons about the technique of explantation and exchange of foldable hydrophilic acrylic lens with good visual outcome in the post operative period. This article describes a case of damaged intraocular lens within the capsular bag. This was successfully managed by snapping the lens into several pieces and explanting the same lens without enlarging the incision. Explantation of lens was followed by implantation of a new foldable lens with good surgical outcome.

Rebound depolarization in single units of the ventral cochlear nucleus: a contribution to grouping by common onset?

Simultaneous grouping by common onset time is believed to be a powerful cue in auditory perception; components that start or stop roughly at the same time are judged as far more likely to have originated from the same source. Here we report a simple experiment designed to simulate a complex psychophysical paradigm first described by Darwin and Sutherland [(1984) Grouping frequency components of vowels. When is a harmonic not a harmonic? Quarterly J of Experimental Psychology: Hum Exp Psychol 36(A):193-208]. It is possible to change the perception of the vowel /I/ to /epsilon/ by manipulating the harmonics around the first formant (F1). Increasing the amplitude of one harmonic around F1 caused the perception of the vowel to change from /I/ to /epsilon/. Extending the increased component before the vowel could, however, greatly reduce this change. The role of neural adaptation in this effect was questioned by repeating the experiment but this time using a 'captor' tone which was switched on with the asynchronous harmonic and off when the vowel started. This time the vowel percept did change in a fashion analogous to the effect of an increase in the amplitude of the fourth harmonic (which is close to F1). This effect was explained by assuming that the captor had grouped with the leading portion of the asynchronous component enabling the remainder of the asynchronous component to be grouped with the remainder of the components. We propose a relatively low-level neuronal explanation for this grouping effect: the captor reduces the neural response to the leading segment of the asynchronous component by activating across-frequency suppression, either from the cochlea, or acting via a wideband inhibitor in the ventral cochlear nucleus. The reduction in neural response results in a release from adaptation with the offset of the captor terminating the inhibition, such that the response to the continuation of that component is now enhanced. Using a simplified paradigm we show that both primary-like and chopper units in the ventral cochlear nucleus of the anesthetized guinea pig may show a rebound in excitation when a captor is positioned so as to stimulate the suppressive sidebands in its receptive field. The strength of the rebound was positively correlated with the strength of the suppression. These and other results are consistent with the view that low-level mechanisms underlie the psychophysical captor effect.

Human auditory nerve compound action potentials and long latency responses.

CONCLUSION: The compound action potential (CAP) is followed by a long latency response (LLR), attributable to the post-auricular musculature. The LLR to one pulse may overlap with the CAP to a subsequent one, contributing to the clinically observed reduction in CAP at high pulse rates. OBJECTIVES: To measure refractory and other influences on CAPs in humans and guinea pigs. MATERIALS AND METHODS: CAPs were obtained from humans using trans-tympanic and extra-tympanic electrocochleography and from anaesthetized guinea pigs. Stimuli were single pulses presented at a slow rate, pairs of pulses, and 100 ms pulse trains where the inter-pulse interval alternated between 4 and 6 ms. RESULTS: For single pulses, the CAP shape was similar across species. For pairs of pulses, the CAP to the second pulse was smaller than that to the first, and decreased with increasing inter-pulse interval in a way that was similar across species. For pulse trains, CAPs were observed in response to each pulse in the train for the guinea pigs, but not for humans. For both filtered and unfiltered single pulses, there was a large LLR in humans, but not in guinea pigs, with peaks at latencies of 10-12 and 20-25 ms. Posture affected the LLR in a way consistent with the post-auricular response.

Parental concern and distress about infant pain.

OBJECTIVE: To describe parent views on infant pain care and to explore relations between parents' experience of their infant's pain care and parental stress. DESIGN: Descriptive, cross sectional survey. SETTING: Nine neonatal units (196 parents) in the United Kingdom and two neonatal units in the United States (61 parents). PARTICIPANTS: Parents of preterm and full term infants admitted to hospital. INTERVENTIONS: Parents completed a three part questionnaire after the second day of the infant's admission and after they had made at least one previous visit to see their infant in the neonatal unit. MAIN OUTCOME MEASURES: Parent concerns about infant pain; parental stress; parent state and trait anxiety. RESULTS: Parents reported that their infants had experienced moderate to severe pain that was greater than they had expected (p < 0.001). Few parents (4%) received written information, although 58% reported that they received verbal information about infant pain or pain management. Only 18% of parents reported that they were shown signs of infant pain, but 55% were shown how to comfort their infant. Parents had numerous worries about pain and pain treatments. Parental stress was independently predicted by parents' estimation of their infant's worst pain, worries about pain and its treatment, and dissatisfaction with pain information received, after controlling for state anxiety and satisfaction with overall care (F = 29.56, df 6, p < 0.001, R(2) = 0.44). The findings were similar across sites, despite differences in infant characteristics. CONCLUSIONS: Parents have unmet information needs about infant pain and wish greater involvement in their infant's pain care. Parent concerns about infant pain may contribute to parental stress.