Photoacoustic resonance by spatial filtering of focused ultrasound transducers

Kang, Dongyel,Lashkari, Bahman,Mandelis, Andreas OPTICAL SOCIETY OF AMERICA 2017 Optics letters Vol.42 No.4

<P>The effect of a spherically focused ultrasound (US) transducer (TD) on photoacoustic (PA) measurements is analytically investigated using the concept of a virtual point detector. The derived analytical results indicate that the limited numerical aperture (NA) of the PA detector takes on the role of spatial filtering of the induced PA waves, which leads to the occurrence of a peak frequency in the PA spectrum. The mathematical description of this phenomenon is similar to the result of resonance peaks of light propagation in dielectrics. This PA resonance peak depends on the NA of the US TD and the absorption coefficient of the PA source. Experimentally measured PA spectra from an ink solution using a frequency-domain PA system verify the PA resonance effect. Finally, we discuss the possibility that previously reported PA resonances interpreted as PA source viscosity might be actually caused by the US TD's spatial filtering. (C) 2017 Optical Society of America</P>

High Histologic Grade and High Ki-67 Expression Predict Phenotypic Alterations in Node Metastasis in Primary Breast Cancers

Pablo Mandó,Manglio Rizzo,Constanza Perez de la Puente,Mercedes Maino,Carolina Ponce,Maria Teresa Pombo,Mora Amat,Maria Victoria Costanzo,Adrian Nervo,Jorge Nadal,Veronica Fabiano,Jose Loza,Carlos Mar 한국유방암학회 2017 Journal of breast cancer Vol.20 No.2

Purpose: Several studies have shown that estrogen receptor (ER) and progesterone receptor (PR) expression and human epidermal growth factor receptor 2 (HER2) expression may vary during tumoral progression. We aimed to describe and compare ER, PR, and HER2 expressions in primary breast tumors and synchronic axillary nodal metastases, and evaluate phenotypic correlations between them. Methods: Patients were identified prospectively through surgical procedures between September 2013 and July 2016. The status of ER, PR, HER2, and Ki-67 were pathologically analyzed in breast cancers and axillary nodal metastases; these patients were classified based on the breast cancer phenotypes into five subgroups. Results: Synchronic axillary nodal metastases were observed in 127 patients. In breast cancers and nodal metastases, correlation analyses of ER, PR, and Ki-67 expression showed a statistical dependence and concordance between these samples was unambiguously demonstrated through Bland-Altman plots for each determination. Primary breast tumors were classified as follows: luminal A, 41.6%; luminal B, 40.0%; luminal B/HER2, 9.6%; HER2, 2.4%; triple negative, 6.4%. Alterations in phenotype were observed in 28% of patients. The most frequent phenotypic alteration was from luminal B to A (36.4%). Ten cases (30.3%) showed alterations with therapeutic implications; six gained HER2 overexpression, and four, hormonal receptor (HR) expression. A moderate strength of agreement (Cohen’s κ coefficient, 0.59; 95% confidence interval, 0.48−0.71) was observed. In multivariate analyses, high histologic grade (odds ratio [OR], 2.79; p<0.047) and high Ki-67 expression (OR, 1.05; p<0.037) were independent factors predictive of phenotypic alterations. Conclusion: Strong correlations were observed in HR and Ki-67 expressions between primary breast tumors and axillary nodal metastases, and a moderate concordance was observed in their phenotypical characteristics. Nevertheless, alterations did exist, and one-third of these changes may have therapeutic implications. The nodal metastases of tumors with high grade and high Ki-67 expression may need to be analyzed, to obtain complete therapeutic information.

Equity or Debt Financing: Does Good Corporate Governance Matter?

Vivek Mande,Young K. Park,Myungsoo Son 한국재무학회 2010 한국재무학회 학술대회 Vol.2010 No.05

We examine whether good corporate governance plays a role in influencing a firm’s financing policy. Specifically, we hypothesize that firms with strong governance tend to prefer stocks over long-term debt. We argue that this is because strong governance reduces information asymmetry between providers of capital (equity investors) and users of capital (managers). While the reduction of information asymmetry has positive connotations for both equity and debt financing, we argue that there is a more significant effect on equity financing. Our test results are consistent with this prediction. We find that equity is preferred to debt financing in firms with high quality governance. This finding contradicts an alternative theory, the pecking order hypothesis, which suggests that firms will issue equity as their last resort. Our results suggest, instead, that strong governance can lower agency costs to a level where equity becomes more attractive to debt as a method of long-term financing.

Geochemical evaluation of groundwater quality of Peshawar Basin, Pakistan

Akhter, Gulraiz,Mand, Bilal A.,Shah, Munir H. Techno-Press 2021 Advances in environmental research Vol.10 No.1

Evaluation of groundwater quality is vital due to its diverse use for several purposes. In the present study, groundwater quality and suitability from the Peshawar basin, Pakistan, were evaluated for drinking and irrigation purposes. The water samples were analysed for major cations (Ca, Mg, Na and K) and anions (chloride, bicarbonate and sulphate) along with other physicochemical parameters (pH, electrical conductivity, total dissolved solids, and total hardness). About 95% of the water samples were found to be within the WHO, US-EPA and Pak-EPA permissible levels for drinking purposes. Seventy percent (70%) of the water samples belonged to the hard water category. Irrigation water quality parameters, such as, chloride, residual sodium bicarbonate, sodium adsorption ratio, percent sodium, magnesium adsorption ratio, Kelly's ration and permeability index were evaluated which demonstrated that the groundwater was highly to moderately suitable for irrigation. A correlation study was conducted to find out the mutual associations among the variables. Piper diagram indicated the overall chemical nature of the study area was calcium-magnesium bicarbonate type. Cluster analysis revealed mutual apportionment of various parameters in the groundwater of the Peshawar basin, Pakistan.

Engineering and Analysis of Nano-Polymer Photovoltaic Solar Cell Processing Based on Bulk Heterojunction Structure

Gankhuleg Majig,Mand-Uugan Majig,Zhan"a O Tan 한국신재생에너지학회 2021 AFORE Vol.2021 No.10

경찰공무원의 폭력피해에 대한 실태와 개선방안

하만득 ( Ha Mand Duck ),설계경 ( Seol Kye Kyoung ) 부산외국어대학교 비교법연구소 2019 比較法學 Vol.31 No.-

최근 우리 사회는 범죄피해자의 인권 보호와 사회적 약자 및 소수자에 대한 배려 와 정책에 많은 관심을 가지고 있다. 하지만 경찰공무원이 해당 피해를 입는 경우 이 에 대한 보상이나 관심은 부족한 현실이다. 범죄현장이나 신고현장에 출동하여 시민 들로부터 물리적인 폭력 및 언어폭력 등의 행위를 경험하는 경찰관들이 증가하고 있다. 하지만 이에 대한 대책이 부족하여 일선 근무자들의 부담이 증가되고 있다. 경찰 관의 법집행이나 경찰 서비스 활동은 시민에 대한 믿음과 상호 신뢰를 바탕으로 가능한데 일부 민원인이나 주취자들의 무례한 행동으로 인해 사기 저하 및 의욕 상실 등의 부정적 경험을 하는 경찰관들이 많아지고 있다. 현재 공무집행방해죄라는 보호 수단이 있지만 이는 현실적으로 만족스럽지 못하다. 특히 행위가 경미하거나 피해정도를 입증하기 힘든 정도의 폭력이라면 더욱 그러하다. 경찰관에 대한 신체를 접촉 행위, 제복을 잡아 당기는 행위, 침뱉기, 뺨때리기, 바닥이나 벽으로 밀치기 등 다소 경미한 것으로 인식되는 행위에 대한 제지방법이 마련되지 않아 많은 갈등을 일으키고 있다. 이에 이 연구는 경찰공무원에 대한 폭력피해의 문제점으로 시민들의 인식문제와 처벌의 약화를 지적하였다. 또한 현장에서 경찰관들이 집행가능한 매뉴얼이나 실효성있는 제도가 부족함을 문제점으로 지적하였다. 이에 대한 개선방안으로는 우선 처벌의 강화를 주장하였다. 처벌의 엄격성은 범죄를 억제하는 가장 기본적이며 입증된 방법이다. 두 번째는 처벌형태의 변화를 제언하였다. 대부분이 벌금형이나 집행유예로 마무리 되는 것은 경찰관에 대한 폭력행위를 억제하지 못한다. 따라서 직장이나 가정에 알리는 등 비공식 억제용인을 통한 예방책을 강구해야 할 것이다. 마지막으로 현장단속 및 내부 규정 마련을 제시하였다. 특히 주취자의 경우 본인행동에 대해 반성할 시간을 가지고 사회생활의 불이익을 안겨주기 위해 유치장 등에 유치하는 것을 제언하였다. 경찰활동의 성공여부는 시민의식 수준에 달려있다. 경찰관의 법집행은 사회 구성원들의 약속에서 비롯되었음을 명심하고 시민의 안전과 경찰관의 효율 적인 직무집행을 위해 많은 교육과 홍보가 병행되어야 할 것이다. Recently, our society has been very interested in protecting human rights of victims of crimes, caring for the weak and minorities. But, when a police officer was injured, there is lack of compensation or attention. Police officers have been sent to crime scenes and reporting sites, on the contrary, there are increasing cases of citizens being violent, but the lack of countermeasures has increased the burden on workers. Law enforcement of the police and police service activities are possible based on trust and mutual trust in citizens. However, there are many cases of negative experiences, such as the low morale of police officers and loss of motivation due to the rude behavior of some complainants or drunk people. In particular, slight action or violence difficult to prove damage are hard to prove. For example, some minor acts, such as physical contact, pulling a uniform, spitting, hitting a cheek, pushing a floor or a wall, etc., to police officers, cause many conflicts because there is no restraining method. Therefore, this researcher pointed out the problem of perception and punishment of citizens as a problem of violence against police officers. also, pointed out that police officers lacked a viable manual and effective system in the field. On how to improve, first, I insisted on reinforcement of punishment. The rigor of punishment is the most basic and proven method of suppressing crime. Second, I suggested a change in the form of punishment. If most of the cases end in fines or probation, this does not suppress violence against police officers. Therefore, preventive measures should be taken through informal deterrents such as informing the workplace or the home. Finally, I suggested setting up site controls and internal regulations. In particular, those who are drunk should give themselves time to reflect on their actions, to be detained in prisons to avoid the disadvantages of social life. The success of the police activities depends on the level of awareness of the citizens. We must keep in mind that the law enforcement of police officers comes from the promises of members of society, and a lot of education and public relations should be combined for the safety of citizens and the efficient execution of police officers.

Bitcoin and stock markets: a revisit of relationship

( Hassanudin Mohd Thas Thaker ),( Abdollah Ah Mand ) 한국파생상품학회 2021 선물연구 Vol.29 No.3

The volatility of bitcoin (BTC) and time horizon is the center point for investment decisions. However, attention is not often drawn to the relationship between BTC and equity indices. Thus, the purpose of this paper is to investigate the volatility and time frequency domain of BTC with stock markets.

Combined analysis and miRNA expression profiles of the flowering related genes in common wild rice (oryza rufipogon Griff.)

Jiao Wang,Yan Long,Jingwen Zhang,Mande Xue,Gege Huang,Ke Huang,Qianhua Yuan,Xinwu Pei 한국유전학회 2018 Genes & Genomics Vol.40 No.8

Common wild rice (Oryza rufipogon Griff.) is the most closely related ancestral species to Asian cultivated rice (Oryza sativa L.). It contains various valuable traits with regard to tolerance to cold, drought and salinity, flowering diversity and many quantitative trait loci with agronomic important traits. Flowering is one of the most important agronomic traits. However, flowering-related transcriptome and how to be regulated by miRNAs have not been estimated in O.rufipogon. To identify how the genes and miRNAs regulating flowering in O.rufipogon. Three O.rufipogon RNA libraries, two vegetative stages (CWRT-V1 and CWRT-V2) and one flowering stage (CWRT-F2) were constructed using leaves tissue and sequenced using Illumina deep sequencing. 27,405, 27,333, 28,979 unique genes were obtained after mapping to the reference genome from CWRT-V1, CWRT-V2 and CWRT-F2, respectively. Then differentially expressed genes (DEGs) were screened and got 1419 unique genes are likely to involve in flower development. Detailed information showed that MADS box and floral meristem identity genes, such as MADS 1, MADS14, Hd1 are involved in common wild rice. Then, combined analysis of miRNA and mRNA expression profiles was performed. Twenty three known miRNA-mRNA pairs and five new candidates were presented an anti-correlationship. Interestingly, 12 miRNAs were negatively correlated with 20 mRNAs encoding flowering-related proteins, indicating that miRNAs regulated target genes to promote flowering in CWRT-F2 group. The results provided here genomic resources for flowering related genes and how these flowering genes were regulated by miRNAs in common wild rice.

Primary user localisation and uplink resource allocation in orthogonal frequency division multiple access cognitive radio systems

Haewoon Nam,Saeed, Nasir,Ben-Ghorbel, Mand,Alouini, Mohamed Slim IET 2015 IET COMMUNICATIONS Vol.9 No.8

<P>In cognitive radio networks, secondary users (SUs) can share spectrum with primary users (PUs) under the condition that no interference is caused to the PUs. To evaluate the interference imposed to the PUs, the cognitive systems discussed in the literature usually assume that the channel state information (CSI) of the link from a secondary transmitter to a primary receiver (interference link) is known at the secondary transmitter. However, this assumption may often be impractical in cognitive radio systems, since the PUs need to be oblivious to the presence of the SUs. The authors first discuss PU localisation and then introduce an uplink resource allocation algorithm for orthogonal frequency division multiple access-based cognitive radio systems, where relative location information between primary and SUs is used instead of CSI of the interference link to estimate the interference. Numerical and simulation results show that it is indeed effective to use location information as a part of resource allocation and thus a near-optimal capacity is achieved.</P>