Worldwide variations in sex ratio of cancer incidence : temporal and geographic patterns

Contexte: Les comparaisons internationales de taux d’incidence du cancer sont des sources importantes d’éléments pouvant aider à générer des hypothèses en lien à l’étiologie du cancer. Les estimations de la variation géographique de l’incidence de cancer peuvent être compromises par des artefacts tels que l’inexactitude et le manque de données complètes portant sur l’incidence du cancer, parmi plusieurs autres. Ces artefacts associés aux taux d’incidence pourront mener à des erreurs au niveau de l’interprétation et de la comparaison des tendances à travers les registres de cancers. Le ratio des sexes (défini comme le rapport du taux d’incidence de cancer masculin divisé par le taux d'incidence féminin) est une mesure qui pourra être moins susceptible d’avoir des ambiguïtés d’interprétation suite à de tels artefacts, dans la mesure où la mesure des cas de cancer est similaire chez les hommes et les femmes. Objectifs: L'objectif principal de cette étude sera donc de conclure quand aux causes qui pourront générer la variabilité dans le ratio des sexes pour des types de cancers spécifiques, à travers temps et lieu, en générant des hypothèses. L’objectif secondaire sera d’explorer la mesure dans laquelle les inégalités de genre entre les pays peuvent fournir des indices sur la qualité des registres de cancer pour les types de cancer sélectionnés, à l'aide du rapport des sexes. Méthodes: L’incidence du cancer dans cinq continents (CI-5), une base de données de registres populationnels de cancer obtenue du Centre international de recherche sur le cancer (CIRC) de l’Organisation mondiale de la santé (OMS), a été utilisée afin d'accéder aux données d’incidence de 30 différents cancers durant 3 périodes de temps (c'est-à-dire 1974-77, 1988-92 et 2003-07) provenant de 77, 142 et 281 registres sur le cancer. Des méthodes descriptives ont été utilisées, soit des modèles à effets mixtes, pour l’étude des tendances temporelles et des variations géographiques au niveau du ratio des sexes. Afin d’explorer le biais en lien au genre, les ratios des sexes pour les cancers du poumon, de la vessie, de l’œsophage et du larynx ont été mis en concordance avec deux indices statistiques, à savoir l’Indice d’inégalité des genres de l’ONU et les estimations mondiales de prévalence du tabagisme de l’OMS. Résultats: Les résultats obtenus à l'aide de modèles à effets mixtes utilisant un nombre égal (soit 76) registres de cancer de longue durée pour chaque année entre 1983 et 2007, après avoir ajusté le ratio des des sexes pour la variation géographique, ont démontré que le cancer du poumon avait le plus haut ratio des sexes en moyenne lors de la première année («baseline») (soit 9.9), suivi de l’œsophage (7.8), la vessie (5.1), le foie (3.8), le pancréas (2.1), le rein (1.9), la leucémie (1.8), le lymphome non hodgkinien (1.8), le cerveau (1.6), le rectum et l’anus (1.5), le côlon (1.2), les yeux (1.2), le mélanome de la peau (0.9), la vésicule biliaire (0.6) et la thyroïde (0.5). Dans les registres de pays ayant une faible inégalité entre les sexes et une prévalence de tabagisme similaire chez les femmes et les hommes (la Suède, la Norvège et le Danemark), le ratio des sexes pour le cancer du poumon était relativement bas (1.2, 1.3 et 1.6). D'un autre côté l’Espagne, tout en ayant une prévalence similaire de tabagisme chez les hommes et les femmes, montrait un ratio des sexes inhabituellement haut pour le poumon (7.1) ainsi que pour d’autres cancers associés au tabagisme (vessie: 14.9, œsophage: 10.7, larynx: 28.2). Les résultats de cette étude tendent à mettre en relief plusieurs types de cancer, notamment celui des reins pour lequel les facteurs de risques connus seront peu susceptibles de pouvoir expliquer pleinement le ratio masculin-féminin de presque 2:1, uniformément stable à travers le temps et les régions. Conclusions: Les facteurs de risque établis dans la littérature dont la prévalence varie dans les deux sexes au niveau mondial, ne semblent pas pouvoir expliquer la stabilité du ratios des sexes pour le cancer du rein au cours des trois décennies. Suite à cette observation, nous avons émis l'hypothèse de certains facteurs endogènes, tels que la génétique ou la variance génétique, pouvant être en mesure d’expliquer la stabilité du ratio des sexes pour ce cancer. Un autre type de cancer, le myélome multiple, s'est lui aussi avéré stable à travers le temps et l’espace (le rôle de la vitamine D a été postulé). Notre étude nous a permis d'identifier des lacunes au niveau de la compréhension des causes de cancer au sein des populations.Context: International comparisons of cancer incidence rates are important sources of evidence for generating hypotheses about cancer etiology. The estimates of geographic variation in cancer incidence can be compromised by artifacts such as imperfect accuracy and completeness of available cancer incidence data among several others. The artifacts associated with incidence rates, can be potentially misleading when interpreting and comparing trends across cancer registries. The Sex Ratio (defined as the male-to-female cancer incidence rate) is one measure that can be less susceptible to ambiguity of interpretations by these artifacts, provided that the ascertainment of cancer cases is similar in males and females. Objectives: Hence, the main aim of this study is to infer as to potential causes that drive sex ratio variability (i.e., the ratio of male to female incidence rates), of type specific cancers across time and geography, generating hypotheses. The secondary aim is to explore the extent to which country-level gender inequalities can provide clues on quality of cancer registries for selected cancer types through sex ratios. Methods: Cancer Incidence in Five Continents (CI-5), a database of population-based cancer registries obtained from International Agency for Research on Cancer (IARC), was used to access incidence data on 30 different cancers in 3 time-periods (i.e., 1974-77; 1988-92 and 2003-07) from 77, 142 and 281 cancer registries. Descriptive methods were used with recourse to mixed-effect regression methods for studying temporal trends and geographic variations in sex ratios. To explore gender bias, sex ratios for cancers of lung, bladder, esophagus, and larynx were tallied with two statistics namely UN’s Gender Inequality Index and WHO’s global tobacco prevalence estimates. Results: In the mixed-effect regression analysis using equal number of 76 long-standing cancer registries in each year from 1983 to 2007, and after adjusting for geographic variation in sex ratio, lung cancer had the highest sex ratio on average in the baseline year (i.e., 9.9), followed by esophagus (7.8), bladder (5.1), liver (3.8), pancreas (2.1), kidney (1.9) leukemia (1.8), non-Hodgkin’s lymphoma (1.8), brain (1.6), rectum and anus (1.5), colon (1.2), eye (1.2), melanoma of skin (0.9), gallbladder (0.6), and thyroid (0.5). In registries belonging to countries, with low gender inequality and similar smoking prevalence in men and women (Sweden, Norway and Denmark), the sex ratio for lung cancer was relatively very low (1.2, 1.3 and 1.6). Whereas Spain with similar prevalence of smoking in men and women, showed an unusually high sex ratio for lung (7.1) as well as for other smoking associated cancers (bladder: 14.9; esophagus: 10.7; and larynx: 28.2). The results of our study also highlight several cancer types, in particular, kidney for which acknowledged and well-known risk factors are unlikely to fully explain the consistently stable male-female ratio of almost 2:1 across time and regions. Conclusions: The well-established risk factors in literature whose prevalence varies worldwide in both sexes, does not seem to decipher the curiously stable sex ratios in cancer of kidney maintained over three decades. This observation has made us to tentatively hypothesize that some endogenous factor such as a gene or gene variant might be able to explain the stable sex ratio of this cancer. Another cancer type, multiple myeloma is also consistently stable across time and place, and where the role of vitamin D has previously been postulated. The study points towards gaps in our understanding of causes of cancer risk in populations

Self-Adaptive Power Control Mechanism in D2D Enabled Hybrid Cellular Network with mmWave Small Cells: An Optimization Approach

Millimeter wave (mmWave) and Device-to-Device (D2D) communications have been considered as the key enablers of the next generation networks. We consider a D2D-enabled hybrid cellular network compromising of $\mu W$ macro-cells coexisting with mmWave small cells. We investigate the dynamic resource sharing in downlink transmission to maximize the energy efficiency (EE) of the priority, or cellular users (CUs), that are opportunistically served by either macrocells or mmWave small cells, while satisfying a minimum quality-of-service (QoS) level for the D2D pairs. In order to solve this problem, we first formulate a self-adaptive power control mechanism for the D2D pairs subject to the interference threshold constraint set for the CUs, while maintaining its minimum QoS level. Subsequently, the original EE optimization problem, which aimed at maximizing the EE for both CUs and D2D pairs, has been broken up into two subproblems that manage the radio resource allocation for D2D pairs and maximize EE exclusively for CUs, in that order. We then propose an iterative algorithm to provide a near-optimal EE solution for CUs

Cellular Services Packages and their Impact on Social Values of Youth

Youth plays a significant role in building of the nation and in the development of a country. Their adoption, aspiration, and objective lead towards change in social value of a culture. Ongoing study investigates the impact of telecom cellular services packages like late night call & unlimited Short Messaging Service (SMS) on the social values of Pakistani youth. In today’s competitive environment cellular companies are mainly targeting youth through their advertisements and would like the youth to get indulge in these activities in order to increase their sales but the point is up to what extent youth showing receptiveness and emotional attachment to these packages. Study was conducted in capital city of Pakistan i.e. Islamabad, mainly considering three famous universities; Iqra University, Bahria University & Foundation University with the sample of 250 respondents; convenient sampling technique is used & results are measured using multiple regression test. Major findings concluded that cellular advertisements of unlimited Short Messaging Service (SMS) and late night call packages have a negative impact on youth but youth is still willing to accept these advertisements as they are negatively attached to the advertisement and use of these packages

Drone-Aided Communication as a Key Enabler for 5G and Resilient Public Safety Networks

Wireless networks comprising unmanned aerial vehicles can offer limited connectivity in a cost-effective manner to disaster-struck regions where terrestrial infrastructure might have been damaged. While these drones offer advantages such as rapid deployment to far-flung areas, their operations may be rendered ineffective by the absence of an adequate energy management strategy. This article considers the multi-faceted applications of these platforms and the challenges thereof in the networks of the future. In addition to providing an overview of the work done by researchers in determining the features of the air-to-ground channel, the article explores the use of drones in fields as diverse as military surveillance and network rehabilitation for disaster-struck areas. It also presents a case study that envisages a scenario in which drones operate alongside conventional wireless infrastructure, thereby allowing a greater number of users to establish a line-of-sight link for communication. This study investigates a power allocation strategy for the microwave base station and the small base stations operating at 28 GHz frequency band. The self-adaptive power control strategy for drones is dependent on the maximum allowable interference threshold and minimum data rate requirements. This study highlights the importance of incorporating the drones in the multi-tier heterogeneous network to extend the network coverage and capacity

Energy-Aware Radio Resource Management in D2D-Enabled Multi-Tier HetNets

Hybrid networks consisting of both millimeter wave (mmWave) and microwave (μW) capabilities are strongly contested for next-generation cellular communications. A similar avenue of current research is device-to-device (D2D) communications, where users establish direct links with each other rather than using central base stations. However, a hybrid network, where D2D transmissions coexist, requires special attention in terms of efficient resource allocation. This paper investigates dynamic resource sharing between network entities in a downlink transmission scheme to maximize energy efficiency (EE) of the cellular users (CUs) served by either (μW) macrocells or mmWave small cells while maintaining a minimum quality-of-service (QoS) for the D2D users. To address this problem, first, a self-adaptive power control mechanism for the D2D pairs is formulated, subject to an interference threshold for the CUs while satisfying their minimum QoS level. Subsequently, an EE optimization problem, which is aimed at maximizing the EE for both CUs and D2D pairs, has been solved. Simulation results demonstrate the effectiveness of our proposed algorithm, which studies the inherent tradeoffs between system EE, system sum rate, and outage probability for various QoS levels and varying densities of D2D pairs and CUs

DOES OPTIMAL CASH HOLDING MATTER IN MAINTAINING AND IMPROVING PROFITABILITY?

ABSTRACT   Purpose: This study was aimed to identify optimal cash holding factors and how they impacted the profitability of Pakistani-listed enterprises

Mentoring and its Effects on Turnover Intensions in Perspective of Pakistan’s Telecom Sector

In today’s era of towering competition the retention of workforce is highly desirable for long term success of any organization. The employees serve as backbone for any organization and are responsible for attaining the laid down objectives of the organization. The ongoing study investigates the effects of mentoring on turnover intensions of employees working in telecom sector of Pakistan. Researchers retrieved data with the help of questionnaires based on five point likert scale from almost 300 employees working in telecom organizations of Pakistan. Multiple regressions were used to analyze the collected data. Result shows that mentoring mostly is negatively associated with turnover intension because employee was not satisfied with mentoring and commitment in employees is only due to experienced learning which helps to develop additional skills in employee

ENHANCING CLIMATE RESILIENCE IN AGRICULTURAL PRACTICES: THE ROLE OF AGRICULTURAL EXTENSION WORKERS IN DISTRICT RAHIM YAR KHAN, PUNJAB, PAKISTAN

Abstract In recent years, the intricate relationship between climate change and its profound impact on agricultural productivity has garnered increasing attention, particularly concerning the pivotal role played by agricultural extension workers. This study delves into climate change mitigation strategies within the realm of agriculture, with a specific focus on the instrumental contributions of agricultural extension workers. Climate change presents a multifaceted challenge to global agricultural systems, exerting significant influences on productivity, crop yields, and food production. Amid these challenges, agricultural extension workers emerge as central figures bridging the chasm between technical knowledge and practical adaptation methods for farmers. This qualitative investigation draws upon a synthesis of existing research and incorporates insights from key informant interviews. By shedding light on the intricate interplay between climate change, agricultural productivity, and the pivotal function of agricultural extension workers, this research aspires to provide a comprehensive understanding of the dynamic relationships between these variables. By facilitating the adoption of climate-resilient techniques, such as cultivating drought-resistant crop varieties, implementing water-efficient irrigation methods, and promoting agroforestry, extension workers empower farmers to mitigate the severe impacts of climate change. Furthermore, extension workers play a pivotal role in bolstering farmers' adaptive capabilities and equipping them with essential skills to navigate increasingly volatile climatic conditions. Studies underscore that farmers who receive training from extension workers report heightened confidence in successfully implementing climate-adaptive strategies