Does investment in palm oil trade alleviate smallholders from poverty in Africa? Investigating profitability from a biodiversity hotspot, Cameroon.

In this study we investigate whether the increasing investment in smallholder oil palm plantations that contributes to deforestation is motivated by financial gains or other factors. We evaluate the financial viability of smallholder farmers selling fresh fruit bunches (FFBs) to intermediaries or agro-industrial companies with mills, or processing the FFBs in artisanal mills to produce palm oil. We use data collected in four oil palm production basins in Cameroon and carried out a life cycle assessment of oil palm cultivation and CPO production to understand financial gains. We use payback period (PBP), internal rate of return (IRR), benefit cost ratio (BCR) and net present value (NPV) for 1 ha of oil palm plantation over 28 years at a base discount rate of 8% to asses viability. Our results show that smallholders make more money processing their FFBs in artisanal mills to produce CPO than selling FFBs to intermediaries or agro-industrial companies with mills. The sensitivity analysis show that land ownership is the single most important parameter in the profitability of investment in palm oil cultivation and trade. In addition to land cost, smallholders suffer from borrowing at high interest rates, high field management costs, while recording low on-farm FFB/processing yields. To improve the financial viability of smallholders investing in oil palm cultivation, measures are needed to encourage them to access land, get loans at reduced interest rates, reduce the cost of field management, adopt good agricultural practices to improve on-farm FFB/processing yields, as well as to generate additional revenue from the sale of other products.

Perineal recurrence of prostate cancer along a brachytherapy needle track: A case report.

Metastatic recurrence in an atypical site, such as the perineum, can occur after prostatectomy, cryotherapy, or brachytherapy, but is uncommon. To our knowledge, this is only the third case of perineal recurrence of prostatic cancer along a low dose rate brachytherapy needle track. A 64-year-old man was referred to an urologist with an increased PSA of 6.9ng/mL in December 2008. There were no urinary symptoms. Prostatic biopsies revealed a Gleason 6 adenocarcinoma (3+3), and he was treated with low dose rate brachytherapy in May 2009. Sixty-seven seeds of iodine 125 were loaded under ultrasound control, and the PSA subsequently fell to a nadir of 1.19ng/mL in November 2015. Eight years (May 2017) after the initial treatment, the PSA rose to 5.2ng/mL. Pelvic MRI and choline PET revealed a nodule in the region of the left internal obturator muscle. Nodule biopsies confirmed prostatic origin. This perineal recurrence is thus most likely related to seeding of tumour cells along the track of a brachytherapy needle. To our knowledge, this is only the fourth case of perineal recurrence of prostatic cancer along a low-dose rate brachytherapy needle track. Perineal recurrence of prostatic cancer along a LDR brachytherapy needle track can occur. Improved imaging techniques may help to identify this type of recurrence earlier and optimise treatment.

Setting the scene for achievable post-2020 convention on biological diversity targets: A review of the impacts of invasive alien species on ecosystem services in Africa.

Invasive alien species (IAS) are known to pose a serious threat to biodiversity, and reduce the ability of ecosystems to provide benefits to humans. In recognition of this threat and to address the impacts of IAS, Parties to the Convention on Biological Diversity (CBD) adopted Aichi Biodiversity Target 9, which is dedicated to the control or eradication of priority IAS and the management of their introduction pathways by 2020. The achievement of Target 9 relies strongly on the commitment and ability of Parties to set ambitious national or regional targets and achive them, the availability of information and the requisite expertise on invasion biology. Now that the global community is gearing for the post-2020 Biodiversity Framework, it is time to take stock and identify opportunities to improve the performance of the African region beyond 2020. We approached this task by reviewing information on the impacts of IAS on ecosystem services in Africa, as a large proportion of Africans directly rely on ecosystem services, particularly in rural areas. Furthermore, we assessed the expertise on IAS in Africa. Our data sources were National Reports of African countries to the CBD, as well as peer-reviewed scientific literature. National Reports under the CBD provide information on measures taken to implement the Convention at country level, as well as progress towards the achievement of set targets. We found National Reports for 48 (about 90%) countries of which 73% provided feedback on IAS indicating commitment to fight IAS. However, there were few studies within peer-reviewed scientific literature looking at impacts of IAS on ecosystem services in Africa and almost half of the authors were non-Africans. This alludes to limited scientific expertise to inform and support IAS management on the continent. Both the National Reports and scientific literature showed that provisioning services were the most negatively affected by IAS. Also, more than 100 species were listed as problematic. More efforts and resources are needed to document IAS impacts across different realms (e.g. marine, terrestrial and freshwater) and for sub-regional bodies so that more integrated strategies and approaches can be developed. This information is also needed to support the development and implementation of national legislative and regulatory initiatives, as well as to report on international obligations such as the Aichi Biodiversity Targets.

[Extra-facial Lever granuloma on a herpes zoster scar: Wolf's isotopic response]. / Granulome de Lever extra-facial sur cicatrice de zona : une réaction isotopique de Wolf.

BACKGROUND: Granuloma faciale (GF), or facial granuloma of Lever, is an uncommon dermatosis occurring classically on the face. We report a case of a GF on zoster scars located on the trunk, which is a highly particular isotopic response. PATIENTS AND METHODS: A 60-year-old man with a sole history of left lumbar zoster presented with a skin lesion present for two months. Clinical examination revealed a 2.5-cm papular erythematous lesion that was both infiltrated and pruritic. This lesion was situated precisely on zoster scars. Lab tests revealed no abnormalities. Histopathologic examination showed an inflammatory process without neovessels but rich in eosinophils with chronic vasculitis and polymorphic infiltrate, on which basis GF was diagnosed. DISCUSSION: GF is a localized form of cutaneous small-vessel vasculitis. Although it usually affects the face, extra-facial locations also exist. The original character of this presentation, aside from the location, is the occurrence of this GF on a zoster scar, which corresponds to Wolf's isotopic response. This phenomenon, described by R. Wolf, comprises the occurrence of a new skin disorder at the site of another unrelated and already healed skin disease, usually herpes. The physiopathology is still unclear. This differs from isomorphic reactions such as Koebner's reaction, which consists of the appearance at an injury site of skin lesions typical of an existing dermatosis but not a new disorder. CONCLUSION: This is a rare case of Wolf's isotopic response with GF, of which, to our knowledge, there are no reports in the literature.

Sudden paraplegia due to spontaneous bleeding in a thoracic epidural angiolipoma and literature review.

BACKGROUND: Spinal angiolipomas are rare epidural tumours that are usually revealed by chronic symptoms of medullar irritation. We report a case of acute paraplegia caused by spontaneous bleeding revealing a thoracic angiolipoma. CASE DESCRIPTION: A 17-year-old male patient with no previous medical history was admitted for acute onset of paraplegia with bladder retention and loss of sensation in the lower limbs, preceded by dorsal pain during the three previous days. MRI showed an enhanced T1-weighted image of a T7-T12 epidural lesion. The T1-weighted isosignal and the T2-weighted hyposignal suggested haemorrhagic complications. Due to a mass effect on the spinal cord, an emergency laminectomy was performed. Histopathological examination of the lesion revealed an angiolipoma with spontaneous bleeding. Clinical outcome was favourable after two months. CONCLUSION: This case is one of the first to be reported, although the clinical presentation is similar to that of other rare reported cases of paraplegia due to spinal compression by tumoural bleeding.

CT findings of complications after abdominal wall repair with prosthetic mesh.

Postoperative complications following prosthetic mesh repair are relatively rare and depend on the type and location of prosthetic mesh. They include abscess, hematoma, seroma, fistula, bowel obstruction, mesh retraction, granuloma and recurrent hernia. Computed tomography (CT) is the imaging examination of choice for the diagnosis of such complications. This pictorial review illustrates the CT presentation of the most and less common postoperative complications following prosthetic mesh repair of the abdominal wall.

Vestibular compensation following vestibular neurotomy.

OBJECTIVES: Four studies assessing vestibular compensation in Menière's disease patients undergoing unilateral vestibular neurotomy, using different analysis methods, are reviewed, with a focus on the different strategies used by patients according to their preoperative sensory preference. MATERIAL AND METHODS: Four prospective studies performed in a university tertiary referral center were reviewed, measuring the pattern of vestibular compensation in Menière's disease patients before and after unilateral vestibular neurotomy on various assessment protocols: postural syndrome assessed on static posturography and gait analysis; perceptual syndrome assessed on subjective visual vertical perception; and oculomotor syndrome assessed on ocular cyclotorsion. RESULTS: Vestibular compensation occurred at variable intervals depending on the parameter investigated. Open-eye postural control and gait/walking returned to normal one month after neurotomy. Fine balance analysis found that visual perception of the vertical and ocular cyclotorsion impairment persisted at long-term follow-up. Clinical postural disturbance persisted only when visual afferents were cut off (eyes closed). These impairments were the expression of a postoperative change in postural strategy related to the new use of visual and non-visual references. CONCLUSIONS: Understanding pre-operative interindividual variation in balance strategy is critical to screening for postural instability and tailoring vestibular rehabilitation.

The usefulness of the Retinomax autorefractor for childhood screening validated against a Danish preterm cohort examined at the age of 4 years.

BACKGROUND AND PURPOSE: Refractometers have gained a foothold in childhood screening for ophthalmic disorders. Given the results of an ophthalmic follow-up of an extremely preterm Danish cohort, the results of the Retinomax autorefractor were further evaluated. MATERIALS AND METHODS: A nationwide cohort of infants born before gestational age 28 weeks (n=178) and 56 term controls were examined at the age of 4 years. Refraction was given as the cycloplegic Retinomax value. For this study, we analysed the equipment's confidence value on the printout and equipment-induced myopization (as the difference between refraction measured before and after topical cyclopentholate 1%), both items hypothetical with a view to having identified factual ophthalmic deviations. RESULTS: Thirty-two of 42 eyes with visual acuity ≤0.4 had high Retinomax confidence values (8-9); the Retinomax values were also high in 10 of 12 children with strabismus and lack of stereopsis. Low values (1-6) were recorded in 11 single eyes, 5 of which were normal (false positives). Three children already known to have low vision were unable to cooperate. The overall mean value for equipment-induced myopization was 1.9 D (range, 0-6.87 D). Myopization showed no correlation with visual acuity and corneal curvature, and a weak positive correlation with refractive value disappeared when the myopic outliers were excluded. CONCLUSIONS: The hand-held Retinomax seemed to be reliable for assessing refraction in 4-year-old children, provided a cycloplegic agent is applied; if used alone, the Retinomax would have missed several cases of ophthalmic deviation during screening. Equipment-induced myopization was not indicative.

Age-related changes in posture control are differentially affected by postural and cognitive task complexity.

The simple postural task of quiet standing, which requires minimal attentional resources, is generally paired with cognitive activity. Competition for attentional resources is a consequence of simultaneously performing balance tasks and cognitive tasks, and impairment of attentional resource allocation with aging leads to increased risks of fall. We investigated age-related changes in posture control during dual task performance, using a paradigm that crossed a static (quiet standing) and a dynamic (keeping balance on a translational force plate) postural task and cognitive tasks of low demand (mental arithmetic) and high demand (spatial memory). Postural performance was analyzed through center-of-pressure displacements using both statistical (body sway area/sway velocity) and nonlinear (wavelet transform) methods in three age groups (younger, middle-aged, and older healthy participants). Results showed that 1) the nonlinear analysis method was more sensitive than the traditional approach in distinguishing performance between age groups, a result that explains discrepancies in the dual-task literature; 2) dual-tasking costs were dependent on both postural task difficulty and cognitive task complexity, corroborating previous investigations; 3) younger adults improved their postural performance during dual-tasking, but older adults lowered their performance; 4) balance recovery strategies in the dynamic postural task appeared to differ in younger versus older adults. Together, our findings on dual-tasking can be interpreted within the conceptual frame of task prioritization: shifting attention away from postural task automates posture control in the younger adults, whereas prioritization of postural task and selection of compensatory strategy are the main characteristics of posture control in the older population.

[Imaging of plexopathy]. / Intérêt de l'imagerie dans le diagnostic des plexopathies.

Recent advances in magnetic resonance imaging (MRI) technology has improved vizualization of the peripheral nerve system, enabling further explorations of plexopathy beyond the physical examination and electrodiagnostic studies. High-resolution MRI is a method of choice, showing diffuse or focal enlargement, hyperintensity on T2-weighted images, altered fascicular patterns, enhancement after gadolinium injection or masses causing infiltration or compression, and signs of muscle denervation. Other techniques are complementary. Ultrasonography can depict a spectrum of lesions and can be coupled with dynamic manoeuvres to explore entrapment syndromes. Positron emission tomography (PET) can be helpful to differentiate between tumor recurrence and postradiation plexopathy. In posttraumatic brachial plexopathy, postmyelographic tomography and MRI are complementary. Traumatic injury, tumor formation, entrapment syndrome, and other conditions illustrate the different techniques available for imaging. Adequate imaging of the brachial and lombosacral plexuses is a useful aid for diagnosis, preoperative assessment and therapeutic planning and follow-up.

Neurogenesis and astrogenesis contribution to recovery of vestibular functions in the adult cat following unilateral vestibular neurectomy: cellular and behavioral evidence.

In physiological conditions, neurogenesis occurs in restricted regions of the adult mammalian brain, giving rise to integrated neurons into functional networks. In pathological or postlesional conditions neurogenesis and astrogenesis can also occur, as demonstrated in the deafferented vestibular nuclei after immediate unilateral vestibular neurectomy (UVN) in the adult cat. To determine whether the reactive cell proliferation and beyond neurogenesis and astrogenesis following UVN plays a functional role in the vestibular functions recovery, we examined the effects of an antimitotic drug: the cytosine-beta-d arabinofuranoside (AraC), infused in the fourth ventricle after UVN. Plasticity mechanisms were evidenced at the immunohistochemical level with bromodeoxyuridine, GAD67 and glial fibrillary acidic protein (GFAP) stainings. Consequences of immediate or delayed AraC infusion on the behavioral recovery processes were evaluated with oculomotor and posturo-locomotor tests. We reported that after UVN, immediate AraC infusion blocked the cell proliferation and decreased the number of GFAP-immunoreactive cells and GABAergic neurons observed in the vestibular nuclei of neurectomized cats. At the behavioral level, after UVN and immediate AraC infusion the time course of posturo-locomotor function recovery was drastically delayed, and no alteration of the horizontal spontaneous nystagmus was observed. In contrast, an infusion of AraC beginning 3 weeks after UVN had no influence neither on the time course of the behavioral recovery, nor on the reactive cell proliferation and its differentiation. We conclude that the first 3 weeks after UVN represent a possible critical period in which important neuroplasticity mechanisms take place for promoting vestibular function recovery: reactive neurogenesis and astrogenesis might contribute highly to vestibular compensation in the adult cat.

Stress axis plasticity during vestibular compensation in the adult cat.

The postural, ocular motor, perceptive and neurovegetative syndromes resulting from unilateral vestibular neurectomy (UVN) symptoms could generate a stress and thereby activate the hypothalamo-pituitary-adrenal (HPA) axis. This study was aimed at determining whether UVN causes changes in the activity of the HPA axis, and if so, evaluating the time course of changes associated with UVN syndrome. At the cellular level, corticotropin-releasing factor (CRF) and arginine vasopressin (AVP) immunoreactivity (Ir) were analyzed and quantified in the paraventricular nucleus (PVN) and the vestibular nuclei (VN) complex of cats killed early (1 and 7 days) or late (30 and 90 days) after UVN. Dopamine-beta-hydroxylase (DbetaH), the enzyme synthesizing noradrenaline was examined in the locus coeruleus (LC) in these same cats. At the behavioral level, the time course of recovery of the postural and locomotor functions was quantified at the same postoperative delays in another group of UVN cats. Results showed a significant bilateral increase in the number of both AVP-Ir and CRF-Ir neurons in the PVN and an increase of DbetaH-Ir neurons in the LC at 1, 7 and 30 days after UVN. This increased number of neurons was no longer observed at 90 days. Conversely, a significant bilateral decrease of CRF-Ir neurons was observed in the VN at these same postlesion times, with a similar return to control values at 90 days. Our behavioral observations showed strong posturo-locomotor functional deficits early after UVN (1 and 7 days), which had recovered partially at 30 days and completely by 90 days postlesion. We demonstrate a long-lasting activation of the HPA axis, which likely reflects a chronic stress, experienced by the animals, which corresponds to the time course of full vestibular compensation, and which is no longer present when the animals are completely free of posturo-locomotor symptoms at 90 days.

Vestibular syndrome: a change in internal spatial representation.

The vestibular system contributes to a wide range of functions from reflexes to spatial representation. This paper reviews behavioral, perceptive, and cognitive data that highlight the role of changes in internal spatial representation on the vestibular syndrome. Firstly, we review how visual vertical perception and postural orientation depend on multiple reference frames and multisensory integration and how reference frames are selected according to the status of the peripheral vestibular system (i.e., unilateral or bilateral hyporeflexia), the environmental constraints (i.e., sensory cues), and the postural constraints (i.e., balance control). We show how changes in reference frames are able to modify vestibular lesion-induced postural and locomotor deficits and propose that fast changes in reference frame may be considered as fast-adaptive processes after vestibular loss. Secondly, we review data dealing with the influence of vestibular loss on higher levels of internal representation sustaining spatial orientation and navigation. Particular emphasis is placed on spatial performance according to task complexity (i.e., the required level of spatial knowledge) and to the sensory cues available to define the position and orientation within the environment (i.e., real navigation in darkness or visual virtual navigation without any actual self-motion). We suggest that vestibular signals are necessary for other sensory cues to be properly integrated and that vestibular cues are involved in extrapersonal space representation. In this respect, vestibular-induced changes would be based on a dynamic mental representation of space that is continuously updated and that supports fast-adaptive processes.

Posture control, aging, and attention resources: models and posture-analysis methods.

This paper reviews the literature on balance and cognitive function in normal aging. The first part provides a general background of dual tasking (postural performance under a concurrent cognitive activity) and summarizes the main relevant models capable of explaining the poorer postural performance of older-healthy adults compared to younger-healthy adults: the cross-domain competition model, the nonlinear interaction model, and the task-prioritization model. In the second part, we discuss the main limitations of the traditional-posturographic analyses used in most of the dual-task investigations and explain how these can account for some discrepancies found in the literature. New methods based on the stabilogram-diffusion analysis and the wavelet transform are proposed as better approaches to understand posture control. The advantages of these new methods are illustrated in young adults and elderly people performing a simple postural task (quiet standing) simultaneously with a mental or a spatial task.

[Diffusion tensor imaging and tractography of central pontine myelinolysis]. / Suivi évolutif d'une myelinolyse centro-pontique en irm de tenseur de diffusion et de tracking de fibres.

OBJECTIVES: To illustrate the value of diffusion tensor imaging and tractography in the diagnosis and follow-up of central pontine myelinolysis. CASE REPORT: We report a case of central pontine myelinolysis in a 29 year old woman, also anorexic, studied using MR Diffusion Tensor Imaging (DTI) and Fibre Tracking (FT) focused on the pons, and compared with the studies of 5 normal volunteers. Tractography showed a swollen aspect of the right corticospinal fiber tract correlating with mild left lower extremity deficit at clinical evaluation. The pontine fibers were posteriorly displaced but intact. The sensory tracts were also intact. Apparent Diffusion Coefficient values were increased and Fractional Anisotropy was decreased in the lesions. Follow up imaging showed persistent abnormal ADC and FA values in the pons although the left cortico-spinal tract returned to normal, consistent with the clinical outcome. CONCLUSION: Diffusion Tensor Imaging MR and Fiber tractography are a new method to analyse white matter tracts. It can be used to prospectively evaluate the location of white matter tract lesions at the acute phase of central pontine myelinolysis and follow up.

Brain MR diffusion tensor imaging and fibre tracking to differentiate between two diffuse axonal injuries.

We report here two cases of diffuse axonal injury (DAI) studied by MR diffusion tensor imaging (DTI) and fibre tracking (FT) focused on the corpus callosum. In one case, DTI and FT pattern matched the diagnosis of broken white matter tracts. In the other case there was a discrepancy between DTI and FT data that showed unaltered white matter tracts with the presence of intra-cellular oedema. These data suggested that DTI and FT are able to differentiate between traumatic cytotoxic oedema and broken fibres in the case of DAI.