Proposal and Implementation of Encounter Data Transmission with Ultrasonic Sensor-based Active Wakeup Mechanism for Energy Efficient Sparse Wireless Sensor Network

International audienceIn this paper, we propose and implement encounter data transmission with an ultrasonic sensor-based active wakeup mechanism for sparse wireless sensor networks (SWSNs), in which sensors are placed sparsely and each sensor is unable to communicate directly. We suppose that an active wakeup mechanism will be more suitable than a low-duty-cycle mechanism for SWSNs, since the collecting node moves around randomly in the sensing field. However, it was not clear whether the collecting node can communicate with the sensor in the short passing-through period. In this paper, we propose to use an ultrasonic sensor for waking up the communication function. We also succeed in developing a real-world sensor node that wakes up only when it detects the closing of the collecting node. We evaluate the detection ratio and the average communication duration of our system in a real-world agricultural application. As a result, we confirm that our system can provide stable communication between the collecting node and the sensor for at least 20 s at 10 kmph and for 10 s at 20 kmph

Early changes in muscle atrophy and muscle fiber type conversion after spinal cord transection and peripheral nerve transection in rats

BACKGROUND: Spinal cord transection and peripheral nerve transection cause muscle atrophy and muscle fiber type conversion. It is still unknown how spinal cord transection and peripheral nerve transection each affect the differentiation of muscle fiber type conversion mechanism and muscle atrophy. The aim of our study was to evaluate the difference of muscle weight change, muscle fiber type conversion, and Peroxisome proliferator-activated receptor-γ coactivatior-1α (PGC-1α) expression brought about by spinal cord transection and by peripheral nerve transection. METHODS: Twenty-four Wistar rats underwent surgery, the control rats underwent a laminectomy; the spinal cord injury group underwent a spinal cord transection; the denervation group underwent a sciatic nerve transection. The rats were harvested of the soleus muscle and the TA muscle at 0 week, 1 week and 2 weeks after surgery. Histological examination was assessed using hematoxylin and eosin (H&E) staining and immunofluorescent staing. Western blot was performed with 3 groups. RESULTS: Both sciatic nerve transection and spinal cord transection caused muscle atrophy with the effect being more severe after sciatic nerve transection. Spinal cord transection caused a reduction in the expression of both sMHC protein and PGC-1α protein in the soleus muscle. On the other hand, sciatic nerve transection produced an increase in expression of sMHC protein and PGC-1α protein in the soleus muscle. The results of the expression of PGC-1α were expected in other words muscle atrophy after sciatic nerve transection is less than after spinal cord transection, however muscle atrophy after sciatic nerve transection was more severe than after spinal cord transection. CONCLUSION: In the conclusion, spinal cord transection diminished the expression of sMHC protein and PGC-1α protein in the soleus muscle. On the other hand, sciatic nerve transection enhanced the expression of sMHC protein and PGC-1α protein in the soleus muscle

Atypical fracture of the tibial plateau

Objective : Only a few cases of insufficiency fractures of the tibial plateau following bisphosphonate use have been reported. The authors report a case with bisphosphonate (BP) -related atypical insufficiency fracture of tibial plateau, which developed delayed union. Patient : A 65-year-old Japanese woman presented with left knee pain without any trauma. She had a 5-year history of risedronate use for primary osteoporosis. Initial X-rays were unremarkable, but magnetic resonance imaging (MRI) confirmed an insufficiency fracture at the left tibial plateau at 3 weeks after the initial visit. Risedronate treatment was stopped because we diagnosed her with a BP-related atypical insufficiency fracture of the tibial plateau. She was treated with rest, a lateral wedge insole and protective weight-bearing with a T-cane for 3 months. Result : At 3-month follow-up, the patient still had a pain and a delayed healing on radiographs. Six months later, X-rays showed that the fracture site had a sclerotic change, but MRI revealed delayed union. At 8-month follow-up, the fracture was healed without any symptoms. Conclusion : All clinicians need to be aware of the delayed healing of atypical insufficiency fracture related with prolonged BP use

Jacobian Adaptation of HMM with Initial Model Selection for Noisy Speech Recognition

An extension of Jacobian Adaptation (JA) of HMMs for degraded speech recognition is presented in which appropriate set of initial models is selected from a number of initial-model sets designed for different noise environments. Based on the first order Taylor series approximation in the acoustic feature domain, JA adapts the acoustic model parameters trained in the initial noise environment A to the new environment B much faster than PMC that creates the acoustic models for the target environment from scratch. Despite the advantage of JA to PMC, JA has a theoretical limitation that the change of acoustic parameters from the environment A to B should be small in order that the linear approximation holds. To extend the coverage of JA, the ideas of multiple sets of initial models and their automatic selection scheme are discussed. Speaker-dependent isolated-word recognition experiments are carried out to evaluate the proposed method

Pelvic Hydatid Disease: CT and MRI Findings Causing Sciatica

Pelvic masses, especially hydatid disease, rarely present with sciatica (1, 2). We present the computed tomography (CT) and the magnetic resonance imaging (MRI) findings of a 49-year-old female patient with presacral hydatid disease, who was evaluated for her sciatica. We also want to emphasize the importance of assessing the pelvis of patients with symptoms and clinical findings that are inconsistent and that cannot be satisfactorily explained by the spinal imaging findings

Novel nano-hydroxyapatite coating of additively manufactured three-dimensional porous implants improves bone ingrowth and initial fixation

Electron beam melting (EBM) has been used to fabricate three-dimensional (3D) porous Ti-6Al-4V surfaces for acetabular cups in total hip arthroplasty. However, there are radiographic concerns regarding poor implant fixation and bone ingrowth around electron beam melted (EBMed) 3D porous cups. We hypothesize that nano-hydroxyapatite (nHA) coating can promote bone ingrowth and thus decrease the occurrence of radiolucent lines around EBMed 3D porous cups. This study aimed to investigate the effect of a novel nHA coating on the biological performance of EBMed 3D porous implants in a beagle transcortical model. Low-porosity (control) and high-porosity 3D porous Ti-6Al-4V implants were manufactured using EBM. Half of the high-porosity implants were coated with nHA without clogging the 3D pores. Implants were inserted into the femoral diaphysis of the beagles. The beagles were euthanized at 4, 8, and 12 weeks postoperatively, and push-out testing was performed. Bone ingrowth was evaluated by histological analysis. Although the increase in porosity alone had no effect on biological behavior, the addition of nHA to high-porosity 3D implants significantly improved early bone fixation and bone ingrowth into the deep region of porous structures compared to low-porosity implants. This is the first report of a novel nHA coating that improved bone ingrowth into the deeper regions of 3D porous implants, which can prevent the occurrence of radiolucent lines around EBMed 3D porous cups.Watanabe R., Takahashi H., Matsugaki A., et al. Novel nano-hydroxyapatite coating of additively manufactured three-dimensional porous implants improves bone ingrowth and initial fixation. Journal of Biomedical Materials Research - Part B Applied Biomaterials. https://doi.org/10.1002/jbm.b.35165

Hypertrophic Chondrocytes Differentiate into Osteogenic Cells

The fate of hypertrophic chondrocytes during endochondral ossification remains controversial. It has long been thought that the calcified cartilage is invaded by blood vessels and that new bone is deposited on the surface of the eroded cartilage by newly arrived cells. The present study was designed to determine whether hypertrophic chondrocytes were destined to die or could survive to participate in new bone formation. In a rabbit experiment, a membrane filter with a pore size of 1 mm was inserted in the middle of the hypertrophic zone of the distal growth plate of ulna. In 33 of 37 animals, vascular invasion was successfully interposed by the membrane filter. During 8 days, the cartilage growth plate was enlarged, making the thickness 3-fold greater than that of the nonoperated control side. Histological examination demonstrated that the hypertrophic zone was exclusively elongated. At the terminal end of the growth plate, hypertrophic chondrocytes extruded from their territorial matrix into the open cavity on the surface of the membrane filter. The progenies of hypertrophic chondrocytes (PHCs) were PCNA positive and caspase-3 negative. In situ hybridization studies demonstrated that PHCs did not express cartilage matrix proteins anymore but expressed bone matrix proteins. Immunohistochemical studies also emonstrated that the new matrix produced by PHCs contained type I collagen, osteonectin, and osteocalcin. Based on these results, we concluded that hypertrophic chondrocytes switched into bone-forming cells after vascular invasion was interposed in the normal growth plate

BMP-2 induces ATF4 phosphorylation in chondrocytes through a COX-2/PGE2 dependent signaling pathway

SummaryObjectiveBone morphogenic protein (BMP)-2 is approved for fracture non-union and spine fusion. We aimed to further dissect its downstream signaling events in chondrocytes with the ultimate goal to develop novel therapeutics that can mimic BMP-2 effect but have less complications.MethodsBMP-2 effect on cyclooxygenase (COX)-2 expression was examined using Real time quantitative PCR (RT-PCR) and Western blot analysis. Genetic approach was used to identify the signaling pathway mediating the BMP-2 effect. Similarly, the pathway transducing the PGE2 effect on ATF4 was investigated. Immunoprecipitation (IP) was performed to assess the complex formation after PGE2 binding.ResultsBMP-2 increased COX-2 expression in primary mouse costosternal chondrocytes (PMCSC). The results from the C9 Tet-off system demonstrated that endogenous BMP-2 also upregulated COX-2 expression. Genetic approaches using PMCSC from ALK2fx/fx, ALK3fx/fx, ALK6−/−, and Smad1fx/fx mice established that BMP-2 regulated COX-2 through activation of ALK3–Smad1 signaling. PGE-2 EIA showed that BMP-2 increased PGE2 production in PMCSC. ATF4 is a transcription factor that regulates bone formation. While PGE2 did not have significant effect on ATF4 expression, it induced ATF4 phosphorylation. In addition to stimulating COX-2 expression, BMP-2 also induced phosphorylation of ATF4. Using COX-2 deficient chondrocytes, we demonstrated that the BMP-2 effect on ATF4 was COX-2-dependent. Tibial fracture samples from COX-2−/− mice showed reduced phospho-ATF4 immunoreactivity compared to wild type (WT) ones. PGE2 mediated ATF4 phosphorylation involved signaling primarily through the EP2 and EP4 receptors and PGE2 induced an EP4-ERK1/2-RSK2 complex formation.ConclusionsBMP-2 regulates COX-2 expression through ALK3–Smad1 signaling, and PGE2 induces ATF4 phosphorylation via EP4-ERK1/2-RSK2 axis

Transition of the stellar initial mass function explored using binary population synthesis

The stellar initial mass function (IMF) plays a crucial role in the determination of the number of surviving stars in galaxies, of the chemical composition of the interstellar medium and of the distribution of light in galaxies. A key unsolved question i