Robust Crop and Weed Segmentation under Uncontrolled Outdoor Illumination

An image processing algorithm for detecting individual weeds was developed and evaluated. Weed detection processes included were normalized excessive green conversion, statistical threshold value estimation, adaptive image segmentation, median filter, morphological feature calculation and Artificial Neural Network (ANN). The developed algorithm was validated for its ability to identify and detect weeds and crop plants under uncontrolled outdoor illuminations. A machine vision implementing field robot captured field images under outdoor illuminations and the image processing algorithm automatically processed them without manual adjustment. The errors of the algorithm, when processing 666 field images, ranged from 2.1 to 2.9%. The ANN correctly detected 72.6% of crop plants from the identified plants, and considered the rest as weeds. However, the ANN identification rates for crop plants were improved up to 95.1% by addressing the error sources in the algorithm. The developed weed detection and image processing algorithm provides a novel method to identify plants against soil background under the uncontrolled outdoor illuminations, and to differentiate weeds from crop plants. Thus, the proposed new machine vision and processing algorithm may be useful for outdoor applications including plant specific direct applications (PSDA)

The Role of Toll-Like Receptor 2 in Inflammation and Fibrosis during Progressive Renal Injury

Tissue fibrosis and chronic inflammation are common causes of progressive organ damage, including progressive renal disease, leading to loss of physiological functions. Recently, it was shown that Toll-like receptor 2 (TLR2) is expressed in the kidney and activated by endogenous danger signals. The expression and function of TLR2 during renal fibrosis and chronic inflammation has however not yet been elucidated. Therefore, we studied TLR2 expression in human and murine progressive renal diseases and explored its role by inducing obstructive nephropathy in TLR2−/− or TLR2+/+ mice. We found that TLR2 is markedly upregulated on tubular and tubulointerstitial cells in patients with chronic renal injury. In mice with obstructive nephropathy, renal injury was associated with a marked upregulation and change in distribution of TLR2 and upregulation of murine TLR2 danger ligands Gp96, biglycan, and HMGB1. Notably, TLR2 enhanced inflammation as reflected by a significantly reduced influx of neutrophils and production of chemokines and TGF-β in kidneys of TLR2−/− mice compared with TLR2+/+ animals. Although, the obstructed kidneys of TLR2−/− mice had less interstitial myofibroblasts in the later phase of obstructive nephropathy, tubular injury and renal matrix accumulation was similar in both mouse strains. Together, these data demonstrate that TLR2 can initiate renal inflammation during progressive renal injury and that the absence of TLR2 does not affect the development of chronic renal injury and fibrosis

Variant G57E of Mannose Binding Lectin Associated with Protection against Tuberculosis Caused by Mycobacterium africanum but not by M. tuberculosis

Structural variants of the Mannose Binding Lectin (MBL) cause quantitative and qualitative functional deficiencies, which are associated with various patterns of susceptibility to infectious diseases and other disorders. We determined genetic MBL variants in 2010 Ghanaian patients with pulmonary tuberculosis (TB) and 2346 controls and characterized the mycobacterial isolates of the patients. Assuming a recessive mode of inheritance, we found a protective association between TB and the MBL2 G57E variant (odds ratio 0.60, confidence interval 0.4–0.9, P 0.008) and the corresponding LYQC haplotype (Pcorrected 0.007) which applied, however, only to TB caused by M. africanum but not to TB caused by M. tuberculosis. In vitro, M. africanum isolates bound recombinant human MBL more efficiently than did isolates of M. tuberculosis. We conclude that MBL binding may facilitate the uptake of M. africanum by macrophages, thereby promoting infection and that selection by TB may have favoured the spread of functional MBL deficiencies in regions endemic for M. africanum

Efficient Targeting of Head and Neck Squamous Cell Carcinoma by Systemic Administration of a Dual uPA and MMP-Activated Engineered Anthrax Toxin

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide. Although considerable progress has been made in elucidating the etiology of the disease, the prognosis for individuals diagnosed with HNSCC remains poor, underscoring the need for development of additional treatment modalities. HNSCC is characterized by the upregulation of a large number of proteolytic enzymes, including urokinase plasminogen activator (uPA) and an assortment of matrix metalloproteinases (MMPs) that may be expressed by tumor cells, by tumor-supporting stromal cells or by both. Here we explored the use of an intercomplementing anthrax toxin that requires combined cell surface uPA and MMP activities for cellular intoxication and specifically targets the ERK/MAPK pathway for the treatment of HNSCC. We found that this toxin displayed strong systemic anti-tumor activity towards a variety of xenografted human HNSCC cell lines by inducing apoptotic and necrotic tumor cell death, and by impairing tumor cell proliferation and angiogenesis. Interestingly, the human HNSCC cell lines were insensitive to the intercomplementing toxin when cultured ex vivo, suggesting that either the toxin targets the tumor-supporting stromal cell compartment or that the tumor cell requirement for ERK/MAPK signaling differs in vivo and ex vivo. This intercomplementing toxin warrants further investigation as an anti-HNSCC agent

Serum Amyloid A Induces NLRP-3-Mediated IL-1β Secretion in Neutrophils

Background/Aims: Serum amyloid A (SAA) is an acute phase reactant with significant immunological activities, including effects on cytokine synthesis and neutrophil chemotaxis. Neutrophils can also release cytokines with proinflammatory properties. IL-1β is a key proinflammatory cytokine, the secretion of which is controlled by inflammasome. We investigated the proinflammatory effects of SAA in vitro in relation to the NLRP3 inflammasome in neutrophils. Methodology/Principal Findings: Human neutrophils isolated form healthy subjects were stimulated with serum amyloid A (SAA). The cellular supernatants were analyzed by western blot using anti-IL-1β or anti-caspase-1 antibodies. IL-1β or Nod-like receptor family, pyrin domain containing 3 (NLRP3) mRNA expressions were analyzed by real-time PCR or reverse transcription-PCR (RT-PCR) method. SAA stimulation induced pro-IL-1β mRNA expression in neutrophils. Furthermore, SAA engaged the caspase-1-activating inflammasome, resulting in the production of active IL-1β. SAA-induced pro-IL-1β expression was marginally suppressed by the Syk specific inhibitor, R406, and SAA-induced pro-IL-1β processing in neutrophils was prevented by R406. Furthermore, SAA-induced NLRP3 mRNA expression was completely blocked by R406. Analysis of intracellular signaling revealed that SAA stimulation activated the tyrosine kinase Syk and mitogen-activated protein kinase (MAPK). Conclusions/Significance: These results demonstrate that the innate neutrophil immune response against SAA involves a two-step activation process: an initial signal promoting expression of pro-IL-1β and a second signal involving Syk-dependent activation of the NLRP3 inflammasome and caspase-1, allowing processing of pro-IL-1β and secretion of mature IL-1β