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1.
Nat Food ; 2(12): 944-956, 2021 12.
Article in English | MEDLINE | ID: mdl-37118238

ABSTRACT

Vertical farming can produce food in a climate-resilient manner, potentially emitting zero pesticides and fertilizers, and with lower land and water use than conventional agriculture. Vertical farming systems (VFS) can meet daily consumer demands for nutritious fresh products, forming a part of resilient food systems-particularly in and around densely populated areas. VFS currently produce a limited range of crops including fruits, vegetables and herbs, but successful implementation of vertical farming as part of mainstream agriculture will require improvements in profitability, energy efficiency, public policy and consumer acceptance. Here we discuss VFS as multi-layer indoor crop cultivation systems, exploring state-of-the-art vertical farming and future challenges in the fields of plant growth, product quality, automation, robotics, system control and environmental sustainability and how research and development, socio-economic and policy-related institutions must work together to ensure successful upscaling of VFS to future food systems.

2.
Proc Math Phys Eng Sci ; 474(2219): 20180335, 2018 Nov.
Article in English | MEDLINE | ID: mdl-30839858

ABSTRACT

Data-driven discovery of dynamics via machine learning is pushing the frontiers of modelling and control efforts, providing a tremendous opportunity to extend the reach of model predictive control (MPC). However, many leading methods in machine learning, such as neural networks (NN), require large volumes of training data, may not be interpretable, do not easily include known constraints and symmetries, and may not generalize beyond the attractor where models are trained. These factors limit their use for the online identification of a model in the low-data limit, for example following an abrupt change to the system dynamics. In this work, we extend the recent sparse identification of nonlinear dynamics (SINDY) modelling procedure to include the effects of actuation and demonstrate the ability of these models to enhance the performance of MPC, based on limited, noisy data. SINDY models are parsimonious, identifying the fewest terms in the model needed to explain the data, making them interpretable and generalizable. We show that the resulting SINDY-MPC framework has higher performance, requires significantly less data, and is more computationally efficient and robust to noise than NN models, making it viable for online training and execution in response to rapid system changes. SINDY-MPC also shows improved performance over linear data-driven models, although linear models may provide a stopgap until enough data is available for SINDY. SINDY-MPC is demonstrated on a variety of dynamical systems with different challenges, including the chaotic Lorenz system, a simple model for flight control of an F8 aircraft, and an HIV model incorporating drug treatment.

3.
J Phys Chem A ; 121(45): 8543-8560, 2017 Nov 16.
Article in English | MEDLINE | ID: mdl-28982240

ABSTRACT

The oxidation of 2-butyl radicals (and to a lesser extent 1-butyl radicals) has been studied over the temperature range of 298-735 K. The reaction of Cl atoms (formed by 360 nm irradiation of Cl2) with n-butane generated the 2-butyl radicals in mixtures of n-C4H10, O2, and Cl2 at temperatures below 600 K. Above 600 K, 2-butyl radicals were produced by thermal combustion reactions in the absence of chlorine. The yields of the products were measured by gas chromatography using a flame ionization detector. Major products quantified include acetone, acetic acid, acetaldehyde, butanone, 2-butanol, butanal, 1- and 2- chlorobutane, 1-butene, trans-2-butene, and cis-2-butene. At 298 K, the major oxygenated products are those expected from bimolecular reactions of 2-butylperoxy radicals (butanone, 2-butanol, and acetaldehyde). As the temperature rises to 390 K, the butanone decreases while acetaldehyde increases because of the increased rate of 2-butoxy radical decomposition. Acetone and acetic acid first appear in significant yield near 400 K, and these species rise slowly at first and then sharply, peaking near 525 K at yields of ∼25 and ∼20 mol %, respectively. In the same temperature range (400-525 K), butanone, acetaldehyde, and 2-butanol decrease rapidly. This suggests that acetone and acetic acid may be formed by previously unknown reaction channels of the 2-butylperoxy radical, which are in competition with those that lead to butanone, acetaldehyde, and 2-butanol. Above 570 K, the yields of acetone and acetic acid fall rapidly as the yields of the butenes rise. Experiments varying the Cl atom density, which in turn controls the entire radical pool density, were performed in the temperature range of 410-440 K. Decreasing the Cl atom density increased the yields of acetone and acetic acid while the yields of butanone, acetaldehyde, and 2-butanol decreased. This is consistent with the formation of acetone and acetic acid by unimolecular decomposition channels of the 2-butylperoxy radical, which are in competition with the bimolecular channels that form butanone, acetaldehyde, and 2-butanol. Such unimolecular decomposition channels would be unlikely to proceed through conventional transition states because those states would be very constrained. Therefore, the possibility that these decomposition channels proceed via roaming should be considered. In addition, we investigated and were unable to fit our data trends by a simplified ketohydroperoxide mechanism.

4.
Blood Cancer J ; 7(2): e536, 2017 02 24.
Article in English | MEDLINE | ID: mdl-28234345

ABSTRACT

CD47, a broadly expressed cell surface protein, inhibits cell phagocytosis via interaction with phagocyte-expressed SIRPα. A variety of hematological malignancies demonstrate elevated CD47 expression, suggesting that CD47 may mediate immune escape. We discovered three unique CD47-SIRPα blocking anti-CD47 monoclonal antibodies (mAbs) with low nano-molar affinity to human and cynomolgus monkey CD47, and no hemagglutination and platelet aggregation activity. To characterize the anti-cancer activity elicited by blocking CD47, the mAbs were cloned into effector function silent and competent Fc backbones. Effector function competent mAbs demonstrated potent activity in vitro and in vivo, while effector function silent mAbs demonstrated minimal activity, indicating that blocking CD47 only leads to a therapeutic effect in the presence of Fc effector function. A non-human primate study revealed that the effector function competent mAb IgG1 C47B222-(CHO) decreased red blood cells (RBC), hematocrit and hemoglobin by >40% at 1 mg/kg, whereas the effector function silent mAb IgG2σ C47B222-(CHO) had minimal impact on RBC indices at 1 and 10 mg/kg. Taken together, our findings suggest that targeting CD47 is an attractive therapeutic anti-cancer approach. However, the anti-cancer activity observed with anti-CD47 mAbs is Fc effector dependent as are the side effects observed on RBC indices.


Subject(s)
CD47 Antigen/genetics , Leukemia/drug therapy , Amino Acid Sequence , Animals , Antibodies, Monoclonal , Female , Humans , Leukemia/genetics , Mice , Mice, Inbred NOD
6.
J Phys Chem A ; 120(20): 3414-23, 2016 May 26.
Article in English | MEDLINE | ID: mdl-27116256

ABSTRACT

The kinetics and mechanism of the reaction of atomic chlorine with ethyl formate [Cl + CH3CH2O(C═O)H, reaction 1] have been examined. These experiments were performed at pressures of 760-950 Torr and temperatures from 297 to 435 K. Reactants and products were quantified by gas chromatography-flame ionization detector (GC/FID) analysis. The initial mixture contained ethyl formate, Cl2, and N2. Cl atoms were generated by UV photolysis of this initial mixture at 360 nm, which dissociates Cl2. The rate constant of reaction 1 was measured at 297 K relative to that of the reaction Cl + C2H5Cl (reaction 2), yielding the rate constant ratio k1/k2 = 1.09 ± 0.05. The final products formed from reaction 1 are ethyl chloroformate, 1-chloroethyl formate, and 2-chloroethyl formate. These products result from the reactions with Cl2 of the three free radicals formed by H atom abstraction from ethylformate in reaction 1. Based on the molar yields of these three chlorinated products, the yields of the three radicals formed from reaction 1 at 297 K are (25 ± 3) mole percent of CH3CH2O(C═O); (67 ± 5) mole percent of CH3CHO(C═O)H; and (8 ± 2) mole percent of CH2CH2O(C═O)H. A second phase of this experiment measured the rate constant of the decarboxylation of the ethoxy carbonyl radical [CH3CH2O(C═O) → CO2 + C2H5, reaction 4] relative to the rate constant of its reaction with Cl2 [CH3CH2O(C═O) + Cl2 → CH3CH2O(C═O)Cl + Cl, reaction 3a]. Over the temperature range 297 to 404 K at 1 atm total pressure, this ratio can be expressed by k4/k3a = 10(23.56±0.22) e(-(12700±375)/RT) molecules cm(-3). Estimating the value of k3a (which has not been measured) based on similar reactions, the expression k4 = 5.8 × 10(12) e(-(12700)/RT) s(-1) is obtained. The estimated error of this rate constant is ± a factor of 2 over the experimental temperature range. This rate expression is compared with recent ab initio calculations of the decarboxylation of the analogous methoxy carbonyl radical.

7.
J Phys Chem A ; 119(34): 9000-17, 2015 Aug 27.
Article in English | MEDLINE | ID: mdl-26221869

ABSTRACT

The equilibrium constants for the Z to E isomerizations of CF3CF═CHF (K1) and CF3CH═CHCF3 (K2) have been measured using GC/FID analysis over the temperature ranges 360­850 and 297­850 K, respectively. At lower temperature, K was determined using Cl atom catalysis. At higher temperature, K was measured without a catalyst. The temperature-dependent expressions are K1 (Z to E) = 1.45(±0.15)e(­[2845(±100)/RT]) and K2 (Z to E) = 1.9(±0.22)e(+[4330(±120)/RT]) (where the gas constant R ≡ 1.986 cal mol(­1) K(­1)). For isomerization 1, the Z (fluorine cis) isomer is 2.85 kcal mol(­1) lower in energy than the E (fluorine trans) isomer, providing another example of the fluorine "cis effect" in olefins. For isomerization 2, the E(trans) isomer is 4.3 kcal mol(­1) lower in energy than the corresponding Z(cis) isomer as is normal for olefins. The isomerization rate constant in a single direction was also measured for each fluorinated compound: k­1(E to Z) = 10(13.87±0.24)e(­59530(±887)/RT) s(­1); and k2(Z to E) = 10(13.89±0.23)e(­58845(±675)/RT) s(­1). To verify the experimental method, cis to trans (k3) and trans to cis (k­3) isomerization rate constants were also measured for cis- and trans-2-butene for comparison to several previous studies. The rate constants determined herein are k3 (cis to trans) = 10(13.95±0.23)e(­63245(±815)/RT) s(­1); and k­3 (trans to cis) = 10(14.32±0.28)e(­64993(±1132)/RT) s(­1). k3 agrees well with four previous measurements and represents the best available rate constant for 2-butene. All errors quoted here are 2σ. The typical total pressure for these experiments was 760 ± 100 Torr. Limited experiments performed at 100 Torr showed no pressure dependence for any of the compounds above 100 Torr. Thus, all isomerization rate constants represent high-pressure limits. The rates of the addition reactions of Cl to the double bonds of CF3CF═CHF (k4) and CF3CH═CHCF3 (k7) (used in Cl catalysis) were also measured in pure N2 and in pure O2. In O2, the rate constants expressions are k4 = 1.56 (±0.22) × 10(­11) e(+(643/RT)) cm3 molecule(­1) s(­1); and k7 = 1.05 × 10(­12) e(+(1874/RT)) cm(3) molecule(­1) s(­1). In N2, k4 and k7 decrease several orders of magnitude as the temperature increases because of the increasing reversibility of the Cl addition reaction, which produces the catalytic effect.

8.
Regul Toxicol Pharmacol ; 72(2): 222-30, 2015 Jul.
Article in English | MEDLINE | ID: mdl-25908511

ABSTRACT

Consumer exposure to chemicals from products and articles is rarely monitored. Since an assessment of consumer exposure has become particularly important under the European REACH Regulation, dedicated modelling approaches with exposure assessment tools are applied. The results of these tools are critically dependent on the default input values embedded in the tools. These inputs were therefore compiled for three lower tier tools (ECETOC TRA (version 3.0), EGRET and REACT)) and benchmarked against a higher tier tool (ConsExpo (version 4.1)). Mostly, conservative input values are used in the lower tier tools. Some cases were identified where the lower tier tools used less conservative values than ConsExpo. However, these deviations only rarely resulted in less conservative exposure estimates compared to ConsExpo, when tested in reference scenarios. This finding is mainly due to the conservatism of (a) the default value for the thickness of the product layer (with complete release of the substance) used for the prediction of dermal exposure and (b) the complete release assumed for volatile substances (i.e. substances with a vapour pressure ⩾10Pa) for inhalation exposure estimates. The examples demonstrate that care must be taken when changing critical defaults in order to retain conservative estimates of consumer exposure to chemicals.


Subject(s)
Consumer Product Safety , Environmental Exposure/analysis , Hazardous Substances , Models, Theoretical , Humans , Inhalation , Risk Assessment , Skin Absorption , Software
9.
Transfus Clin Biol ; 22(1): 30-6, 2015 Mar.
Article in French | MEDLINE | ID: mdl-25595822

ABSTRACT

INTRODUCTION: Knee arthroplasty causes significant blood loss. Different blood-saving measures exist like retransfusion of unwashed salvaged blood. Some studies question the quality of this blood and in particular its ability to clot. These studies use "static" coagulation tests reflecting only partially the reality, unlike viscoelastic methods. The main objective of this study was to evaluate the salvaged blood thromboelastometric profile using ROTEM® system and to compare these results with patient venous blood. MATERIALS AND METHODS: We performed an observational, prospective, single-center study conducted over 3 months in 2013. Agreement of local ethical committee and patient consent were obtained beforehand. All adult patients who underwent a primary total knee arthroplasty were included. A thromboelastometric profile and standard laboratory tests (hemoglobin, platelets count, PT, aPTT, fibrinogen) were performed in the same time on patient venous blood and on unwashed salvaged blood in the PACU. RESULTS: Twenty patients were included. The median duration of surgery was 93 minutes. Thirteen patients (65%) received tranexamic acid during procedure. The median volume of shed blood was 225 mL. Two patients (10%) received a reinfusion. Analysis of shed blood showed a major deficiency of clotting factor in standard biology (PT<10%) and an absence of clot formation in thromboelastometric test (In-tem®, Ex-tem®, Fib-tem® or Ap-tem®). Compared to venous blood, shed blood had significantly lower hemoglobin levels: 8.8 vs 13.5 g/dL (P<0.0001). Allogenic transfusion concerned 5% of patients. DISCUSSION: In this work, we confirmed that shed blood was naturally uncoagulable probably due to a multifactorial mechanism involving a major clot factor deficiency and an activation of fibrinolysis.


Subject(s)
Arthroplasty, Replacement, Knee , Thrombelastography , Aged , Female , Humans , Male , Operative Blood Salvage , Prospective Studies , Veins
10.
Minerva Anestesiol ; 81(8): 876-84, 2015 Aug.
Article in English | MEDLINE | ID: mdl-25415352

ABSTRACT

BACKGROUND: Because of restricted information given by monitoring solely intracranial pressure and cerebral perfusion pressure, assessment of the cerebral oxygenation in neurocritical care patients would be of interest. The aim of this study was to determinate the correlation between the non-invasive measure regional saturation in oxygen (rSO2) with a third generation NIRS monitor and an invasive measure of brain tissue oxygenation tension (PbtO2). METHODS: We conducted a prospective, observational, unblinded study including neurocritical care patients requiring a PbtO2 monitoring. Concomitant measurements of rSO2 were performed with a four wavelengths forehead sensor (EQUANOX Advance®) of the EQUANOX® 7600 System. We determined the correlation between rSO2 and PbtO2 and the ability of the rSO2 to detect ischemic episodes defined by a PbtO2 less than 15 mmHg. The rSO2 ischemic threshold was 60%. RESULTS: During 2 months, 8 consecutives patients, including 275 measurements, were studied. There was no correlation between rSO2 and PbtO2 (r=0.016 [-0.103-0.134], r2=0.0003, P=0.8). On the 86 ischemic episodes detected by PbtO2, only 13 were also detected by rSO2. ROC curve showed the inability for rSO2 to detect cerebral hypoxia episodes (AUC=0.54). CONCLUSION: rSO2 cannot be used as a substitute for PbtO2 to monitor cerebral oxygenation in neurocritical care patients.


Subject(s)
Brain Chemistry , Critical Care/methods , Hypoxia, Brain/diagnosis , Nervous System Diseases/therapy , Oximetry/methods , Oxygen Consumption , Adult , Aged , Female , Forehead , Humans , Hypoxia, Brain/metabolism , Male , Middle Aged , Prospective Studies , Spectroscopy, Near-Infrared , Young Adult
11.
Med Sante Trop ; 24(2): 214-6, 2014.
Article in French | MEDLINE | ID: mdl-24854187

ABSTRACT

Intraosseous infusion is increasingly used as an alternative to intravenous infusion. It is recommended for the cardiac arrest of a child in the first instance and after two failed attempts of intravenous infusion in the cardiac arrest of adults. Its rapid use and its low failure rate justify its use in all life-threatening emergencies. It can be used to administer the same treatments as intravenous infusion. It does, nonetheless, present some rare complications, such as acute leg ischemia by extravasation of epinephrine, as we report here. Awareness of these complications is necessary to ensure compliance with the rules of placing this type of infusion.


Subject(s)
Epinephrine/adverse effects , Heart Arrest/drug therapy , Ischemia/chemically induced , Leg/blood supply , Djibouti , Epinephrine/administration & dosage , Female , Humans , Infant , Infusions, Intraosseous/adverse effects
12.
J Phys Chem A ; 118(18): 3237-42, 2014 May 08.
Article in English | MEDLINE | ID: mdl-24734922

ABSTRACT

The rate constant of the reaction Cl + CFCl2H (k1) has been measured relative to the established rate constant for the reaction Cl + CH4 (k2) at 760 Torr. The measurements were carried out in Pyrex reactors using a mixture of CFCl2H, CH4, and Cl2 in either N2 or N2/O2 diluent. Reactants and products were quantified by GC/FID analysis. Cl atoms were generated by irradiation of the mixture with 360 nm light to dissociate the Cl2 for temperatures up to ~550 K. At higher temperature, the Cl2 dissociated thermally, and no irradiation was used. Over the temperature range 298-670 K, k1 is consistently a factor of ~5 smaller than that of k2 with a nearly identical temperature dependence. The optimum non-Arrhenius rate constant is represented by the expression k1 = 1.14 × 10(-22) T(3.49) e(-241/T) cm(3) molecule(-1) s(-1) with an estimated uncertainty of ±15% including uncertainty in the reference reaction. CFCl3 formed from the reaction CFCl2 + Cl2 (k3) is the sole product in N2 diluent. In ~20% O2 at 298 K, the CFCl3 product is suppressed. The rate constant of reaction 3 was measured relative to that of reaction 4 [CFCl2 + O2 (k4)] giving the result k3/k4 = 0.0031 ± 0.0005 at 298 K. An earlier experiment by others observed C(O)FCl to be the major product of reaction channel 4 [formed via the sequence, CFCl2(O2) → CFCl2O → C(O)FCl + Cl]. Our current experiments verified that there is a Cl atom chain reaction in the presence of O2 as required by this mechanism.

14.
Med Sante Trop ; 23(4): 417-20, 2013.
Article in French | MEDLINE | ID: mdl-24333748

ABSTRACT

INTRODUCTION: The use of the World Health Organization surgical safety checklist, mandatory in operating rooms (OR) in France, significantly reduces morbidity and mortality. Our objective was to evaluate the use of this checklist in the OR of a French military hospital in Djibouti (Horn of Africa). METHODS: The study was performed in three stages: a retrospective evaluation of the checklist use over the previous two months, to assess the utilization and completeness rates; provision of information to the OR staff; and thereafter, prospective evaluation for a one-month period of checklist use, the reasons for non-compliance, and the cases in which the checklist identified errors and thus prevented serious adverse events. RESULTS: The initial utilization rate was 49%, with only 24% complete. After staff training and during the study these rates reached 100% and 99%. The staff encountered language difficulties in 53% of cases, and an interpreter was available for 81% of them. The capacity of the surgical safety checklist to detect serious adverse events was highlighted. CONCLUSION: The utilization and completeness rates were initially worse than those observed in metropolitan French ORs, but a simple staff information program was rapidly effective. Language difficulties are frequent but an interpreter is often available, unlike in developed countries where language problems are uncommon and the availability of interpreters difficult. Moreover, this study illustrates the ability of the checklist to detect and therefore prevent potentially serious adverse events.


Subject(s)
Checklist/statistics & numerical data , Communication Barriers , Guideline Adherence , Operating Rooms/statistics & numerical data , Patient Safety , Africa/ethnology , Anesthesia/standards , Djibouti , Feasibility Studies , France/ethnology , Hospitals, Military/standards , Humans , Intraoperative Care/standards , Language , Operating Rooms/organization & administration , Patient Safety/standards , Postoperative Care/standards
15.
Med Sante Trop ; 23(2): 211-6, 2013 May 01.
Article in French | MEDLINE | ID: mdl-23842640

ABSTRACT

BACKGROUND: The features of heart failure (HF) in Djibouti have not been well described. We sought to document the current patterns of HF here. METHODS: We prospectively included Djiboutian adults hospitalized for HF in the French Military Hospital (Djibouti) from August 2008 through December 2010. RESULTS: Of 1688 adults hospitalized in the medical department, 45 (2.7%) had symptomatic HF: 38 (84%) men, mean age 55.8 years (range 27-75). Twenty-five (56%) patients were initially hospitalized for acute pulmonary edema. The underlying diseases included coronary artery disease (CAD) (62%), hypertensive heart disease (18%), rheumatic valvular disease (13%), and primary dilated cardiomyopathy (7%). Their cardiovascular risk factors included tobacco use (53%), hypertension (69%), diabetes (47%), and hypercholesterolemia (51%). Patients in the CAD group were older, and had diabetes more often (p<0.01). All khat chewers (53%) were males and smokers. Mean left ventricular ejection fraction (LVEF) was 39 ± 14%. During follow-up (14.4 ± 9 months), 8 (18%) patients died, 9 (20%) were again hospitalized for HF, and 3 (7%) had ischemic strokes. One month after discharge, the New York Heart Association (NYHA) class was II for 40%, III for 44%, and IV for 16%. Higher NYHA classes and dilated cardiomyopathy were both associated with poorer outcomes (p<0.03). CONCLUSION: In hospitalized Djiboutians, most HF patterns are similar to those in industrialized countries. CAD is more prevalent than previously reported in African patients with HF.


Subject(s)
Heart Failure/epidemiology , Adult , Aged , Djibouti , Female , Humans , Male , Middle Aged , Prospective Studies
16.
Int J Cardiol ; 168(3): 2255-63, 2013 Oct 03.
Article in English | MEDLINE | ID: mdl-23474245

ABSTRACT

OBJECTIVE: Twenty-four hour ambulatory blood pressure (ABP) is superior to office blood pressure (BP) in predicting cardiovascular events. However, its use to optimise BP control in treated hypertensive patients is less well examined. DESIGN AND METHOD: In this observational study conducted in 899 general practitioners' offices, 4078 hypertensive patients with uncontrolled office BP were included. Antihypertensive therapy was intensified and after 1 year office BP and 24-hour ABP were measured to categorise patients according to the ESC/ESH 2007 guidelines. RESULTS: In this cohort (mean office BP 156/90 mmHg, mean ABP 146/85 mmHg), 2059 out of 4078 patients (50.5%) had controlled office BP (<140/90 mmHg) at 1 year examination. Of these apparently controlled patients (N=2059), 1339 (65.8%) had 24-hour ABP ≥ 130/80 mmHg, indicating masked hypertension (32.9% of all treated patients). In the prespecified subgroups the prevalence of masked hypertension was the following: diabetes 28.2%, CVD 29.1%, and CKD 32.1%. White coat hypertension (24h-ABP<130/80 mmHg and office BP ≥ 140/90 mmHg) was found in 12.4% (N=233) of patients with elevated office BP (6.1% of all treated patients), and in 5.7% of the diabetic subgroup, 5.6% CVD and 7.1% CKD. Discrepancies in BP categorisation between office BP and 24-hour ABP were high; all subjects 52.8%, diabetes 50.0%, CVD 49.0% and CKD 50.4%. CONCLUSION: In hypertensive patients on therapy, 2 out of 3 with apparently controlled office BP had masked hypertension, suggesting a more aggressive therapy, and 1 out of 8 with elevated office BP had white coat hypertension potentially falsely forcing physicians to intensify therapy. The 3A Registry is listed under clinicaltrials.gov, NCT01454583.


Subject(s)
Antihypertensive Agents/therapeutic use , Blood Pressure Monitoring, Ambulatory , Blood Pressure/physiology , Hypertension/diagnosis , Aged , Female , Follow-Up Studies , Humans , Hypertension/drug therapy , Hypertension/physiopathology , Male , Middle Aged , Prospective Studies , Reproducibility of Results , Time Factors
18.
Int J Parasitol Parasites Wildl ; 2: 54-61, 2013 Dec.
Article in English | MEDLINE | ID: mdl-24533316

ABSTRACT

The roles and epidemiological features of tick-borne protozoans are not well elicited in wildlife. Babesia spp. are documented in many domestic animals, including cattle, horses, pigs, dogs and cats. Three cases affecting eastern grey kangaroos are described. The kangaroos exhibited neurological signs, depression and marked anaemia, and microscopic examination of blood smears revealed intraerythrocytic piroplasms. One to seven intraerythrocytic spherical, oval, pyriform and irregularly-shaped parasites consistent with Babesia spp. were seen in the blood smears and the percentage of infected erythrocytes was estimated to be approximately 7% in each case. Data suggest that the tick vector for this kangaroo Babesia sp. is a Haemaphysalis species. For Case 2, ultrastructural examination of the erythrocytes of the renal capillaries showed parasites resembling Babesia spp. and 18 of 33 erythrocytes were infected. DNA sequencing of the amplified 18S rDNA confirmed that the observed intraerythrocytic piroplasms belong to the genus Babesia. The phylogenetic position of this new kangaroo Babesia sp. (de novo Babesia macropus), as a sister species to the new Australian woylie Babesia sp., suggests a close affinity to the described Afro-Eurasian species Babesia orientalis and Babesia occultans suggesting perhaps a common ancestor for the Babesia in kangaroos.

19.
Med Sante Trop ; 22(3): 297-301, 2012.
Article in French | MEDLINE | ID: mdl-23174484

ABSTRACT

OBJECTIVES: Acute myocardial infarction (AMI) is a life-threatening emergency. In Africa, the increasing prevalence of cardiovascular risk factors is leading to an epidemiological transition. No data have yet been reported about AMI in Djibouti. PATIENTS AND METHODS: This study prospectively included all patients with acute coronary syndrome and persistent ST segment elevation admitted to the emergency department of Bouffard Military Hospital in Djibouti from January 2009 through December 2010. It analyzed their clinical data and management. RESULTS: The study included 35 patients. Their mean age was 52 ± 11 years [range: 29-76]. The sex ratio was 7.7 (men/women). Cardiovascular risk factors were: hypercholesterolemia (83%), tobacco use (60%), khat chewing (57%), diabetes (49%), hypertension (46%), and heredity (20%). AMI was anterior in 40% of cases. Fifteen patients (43%) arrived within 12 hours after the onset of symptoms (average 5 hours); thrombolysis was successful for 11 of them (73%). Seven patients (20%) died over the entire follow-up (11.3 ± 9 months), 5 within the first month. Mortality was significantly associated with diabetes (p<0.01), initial severe clinical complications (p<0.01) and initial low left ventricular ejection fraction (p<10(-6)). CONCLUSION: Patients with AMI in Djibouti are 10 to 15 years younger than in Western countries. Their high level of cardiovascular risk is remarkable. Khat use did not significantly affect prognosis. The high mortality rate was similar to rates reported before the percutaneous coronary angioplasty era.


Subject(s)
Myocardial Infarction , Adult , Aged , Djibouti/epidemiology , Female , Humans , Male , Middle Aged , Myocardial Infarction/diagnosis , Myocardial Infarction/epidemiology , Prospective Studies , Time Factors
20.
Med Sante Trop ; 22(2): 213-6, 2012.
Article in French | MEDLINE | ID: mdl-22894893

ABSTRACT

Hemorrhagic shock requires early aggressive treatment, including transfusion of packed red blood cells and hemostatic resuscitation. In austere environments, when component therapy is not available, warm fresh whole-blood transfusion is a convenient treatment. It provides red blood cells, clotting factors, and functional platelets. Therefore it is commonly used in military practice to treat hemorrhagic shock in combat casualties. At Bouffard Hospital Center in Djibouti, the supply of packed red blood cells is limited, and apheresis platelets are unavailable. We used whole blood transfusion in two civilian patients with life-threatening non-traumatic hemorrhages. One had massive bleeding caused by disseminated intravascular coagulation due to septic shock; the second was a 39 year-old pregnant woman with uterine rupture. In both cases, whole blood transfusion (twelve and ten 500 mL bags respectively), combined with etiological treatment, enabled coagulopathy correction, hemorrhage control, and satisfactory recovery.


Subject(s)
Blood Transfusion , Resuscitation , Shock, Hemorrhagic/therapy , Adult , Djibouti , Female , Humans , Male
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