N. S. A. Mustafa

• Doctor of Agriculrrual science
• Professor (Full) at National Research Centre

Timely harvesting of fresh apples faces challenges due to labour shortage, and the modern approach of robotic harvesting has the potential to address this issue. The prevailing process of apple harvest robotics could not meet the demands of practical applications, mainly due to the lack of a suitable manipulator, because the existing ones are assoc...

This research, spanning the 2021 and 2022 seasons, aimed to explore the impact of vermicomposting on the growth and productivity of Mango trees (cv. Keitt) cultivated in sandy soil at Ahmed Orabi Agricultural region, El-Obour City, Cairo Governorate, Egypt. The selected trees underwent various treatments, including water (control), vermicomposting...

Currently, apple harvesting primarily relies on manual picking, which presents issues such as low efficiency, high costs, and frequent occupational health problems. As the labor shortage intensifies, the timely harvest of fresh apples faces significant challenges, making the use of robots to replace human labor an inevitable trend. With the groundb...

The apple in-field sorting system can reduce post-production costs and enhance the competitiveness of China’s apple industry. Our laboratory has developed computerized imaging-based apple in-field sorting equipment consisting of a variable-pitch screw conveyor, a computerized imaging system, and a sorting actuator. To achieve efficient sorting of a...

In a greenhouse belong to Pomology Department, National Research Centre, Cairo, Egypt conducted the present work during 2022/2023aims of this study was to investigate the effect of nanotechnology on improving the efficiency of jojoba oil biological control of nematodes and root environmental protection. The investigated concentrations of treatments...

.Various synthetic nematicides are currently used effectively in the control of plant parasitic nematodes. However, these nematicides have adverse effects on humans and the environment. Neem oil is eco-friendly alternatives to synthetic nematicides. The effectiveness of repeated neem oil application in suppressing the root-knot nematodes infestatio...

Background and Objective: Vermicompost technology technique can play as a cost-effective and safe mechanism to agro-waste disposal. The current study aimed to study the impact of vermicompost application on agronomic behaviour of tomato crop and soil health. Materials and Methods: An experiment was conducted out in National Research Centreʼs farm,...

Climatic change and its negative impacts may consider as one of the big global challenges, and eliminate soil and water availability time by time. Adding organic fertilizers (i.e. vermicompost) as soil amelioration may consider as one of effective approaches in order to recover soil degradation and enhance water retention in soil. Through vermicomp...

The current study aimed to study the effect of foliar application of nano-NPK fertilizer to one-year-old Fig trees (cv. Black Mission) in terms of tree growth performance as well as on soil microbial activity. The investigated concentrations of nano-NPK were 100, 200, 300, 400 and 500 ppm in addition to the control treatment applied for two seasons...

This study was conducted with the aim of making a new approach to plant fertilization based on nano-fertilizers and vermicompost and its positive effect on soil health. This work was carried out in the experimental research shade house of National Research Centre, Dokki, Giza, Egypt during (2020- 2021). For this purpose, healthy 5 years old fig see...

World face several challenges the most decisive climatic changes , freshwater poverty and poor usage efficiency for natural resources (soil & water) particularly in developing countries. Applying Nanotechnology may represent a smart mechanism toward sustainable agricultural. Much efforts have been exerted to utilizing nano-technology and producing...

Root-knot nematodes (RKNs) (Meloidogynespp) is the most economically destructive species. A pot experiment was conducted to assess the suppressing potential of three vermicompost types of different plant residues origin on (RKNs) (Meloidogyne incognita) in tomato cultivar by inoculation in prepared soil. Three vermicompost types CD (Cow dung) alone...

Organic fertilizer usage is been introduced into agricultural practices for preventing the damaging effects of chemical fertilizers. Present study investigated the beneficial role of organic fertilizer (nano-vermicompost) on the growth, oxidative stress parameters, antioxidant and nitrogen metabolism, osmolyte accumulation and mineral elements in t...

Drought is a major environmental threat limiting worldwide crop production. Drought stress affects the tobacco quality and yield; therefore, the current research studies were undertaken to investigate the effectiveness of arbuscular mycorrhizal fungi (AMF) under drought stress on morphological and biochemical attributes of tobacco (Nicotiana tabacu...

In vitro shoot tips of plum (Prunus Salicina) cv."Santa Rosa" was used to investigate the effect of some growth regulators on multiplication and rooting processes. Benzylaminopurine (BAP) at different concentrations (0.00, 0.25, 0.50 and 1.00 mg/l) was studied for their ability to induce plum shoot multiplication. In addition, double, one and half...

Salinity is a major cause of crop losses worldwide. Acetylcholine (ACh) can ameliorate the adverse effects of abiotic stresses on plant growth, including salinity stress; however, the underlying molecular mechanisms of this process are unclear. Here, seedlings of Nicotiana benthamiana grown under normal conditions or exposed to 150 mmol L⁻¹ NaCl sa...

Vermicompost is considered one of high-quality organic fertilizer forms. The aim of the current work + water hyacinth) and (cow dung + duckweed) at the Central Lab for aquaculture research (CLAR), Agricultural Research Center. The samples of these vermicompost types were delivered was to investigate the role of aquatic plants (i.e. water hyacinth a...

The role of arbuscular mycorrhizal fungus (AMF, Glomus versiforme) in amelioration of drought-induced effects on growth and physio-biochemical attributes in maize (Zea mays L.) was studied. Maize plants were exposed to two drought regimes, i.e., moderate drought (MD) and severe drought (SD), with and without AMF inoculation. Drought at both levels...

A huge amount of agricultural waste produced in agri-aquacultural farms could play a positive and important role in different aspects starting from decreasing rate of soil degradation till raising soil fertility besides maintaining activity and diversity of microorganism community in soil, thereby good and effective managing of recycling these agri...

Current study aimed to maximize multiplication rate, growth parameters and producing superior plantlets which can tolerate acclimatization conditions of Conadria fig cultivar through utilizing of Thidiazuron (TDZ), isopentenyladenine (2iP) separately. Shoots- that passed establishment stage- were cultured on MS medium that contained different conce...

As continuously efforts to maximize utilization from nan-science in agriculture sector, one–year old olive(Aggiz cv.) seedlings (grown in shade house of Pomology Dept, National Research Centre, Giza, Egypt) were been subjected during two growth seasons (2016-2017) to current study that came out to test for how far can substitute convenient fertiliz...

This experiment conducted on ―kalamata olive seedlings grown at the greenhouse of National Research Centre, Dokki, Giza governorate, Egypt. This investigation was aimed to study the effect of applying nano-fertilizers, as complementary technique for fertilizer program, on growth performance and nutrients status of kalamata olive seedlings. Treatmen...

In vitro regenerated shoots of olive (Coratina cv.) from shoot tip establishment stage were cultured individually on olive medium supplemented with 2.0 mg/L 6-benzylaminoproline (BAP). Putrescine and glutamine at 50 and 100 ppm were tested during proliferation and rooting stages. Data indicated that putrescine and glutamine at higher concentration...

As continuously efforts to maximize utilization from nano-science in agriculture sector, one-year old fig (cv. Sultani) seedlings (grown in shade house of Pomology Dept., National Research Centre, Giza, Egypt) were been subjected during two growth seasons (2016/17) to current study that tests hypothesis concern with full replacement conventional mi...

This experiment was carried out during two successive seasons to study the effect of different irrigation rates with two shading net colors on Keitte mango trees grown under sandy soil conditions. Two irrigation rates (9 and 6 drippers/tree) were examined under blue and white colors of shading net, whereas control trees were exposed for sunlight an...

The shoots regenerated from shoot tips of three Fig cultivars (Aboudi, Gizy and Sultany) plantlets from the establishment stage were cultured individually on Murashige and Skoog (MS) medium supplemented with0.5 mg/l 6- benzylaminoperine. Different cytokinin types (kinetin, 6- benzylominopurine, 2ip (Isopentyl adenine) and cytokinin like compound (T...

Shoots regenerated from shoot tip of BlackMission and Conadria fig cultivars plantlets from the establishment stage were cultured on Murashige and Skoog medium. Different cytokinin types (6-bnezylominopurine (BAP), 2ip (6-(γ,γ-Dimethylallylamino)purine) and kinetin) and cytokinin like compound (TDZ) were tested, in addition, Murashige and Skoog (MS...

This study was carried out during 2014, on one years old of Fig seedlings c.v White Adci grown in shade house of pomology department, National Research Centre, humate potassium and Green-power (Vinasse 80% + Soyabean amino acid 20%) were applied in different application (soil application, foliar application and combination between two techniques) a...

Let d and t be fixed positive integers, and let \(K^d_{t,\ldots ,t}\) denote the complete d-partite hypergraph with t vertices in each of its parts, whose hyperedges are the d-tuples of the vertex set with precisely one element from each part. According to a fundamental theorem of extremal hypergraph theory, due to Erdős [7], the number of hyperedg...

We show that the size-sensitive packing lemma follows from a simple modification of the standard proof, due to Haussler and simplified by Chazelle, of the packing lemma.

SIAM Journal on Computing, to appear.

In this paper, we introduce the notion of k-centerpoints for any set P of n points in Rd. These unify and generalize previous results such as the classical centerpoint theorem,1 and the recently-proven ray-shooting theorem.2 We define two variants: affine k-centerpoints, and topological k-centerpoints. We prove their equivalence in R2, and conjectu...

Instant radiosity methods rely on using a large number of virtual point lights (VPLs) to approximate global illumination. Efficiency considerations require grouping the VPLs into a small number of clusters that are treated as individual lights with respect to each point to be shaded. Two examples of clustering algorithms are Lightcuts [WFA*05] and...

We present a novel algorithm, IlluminationCut, for rendering images using the many-lights framework. It handles any light source that can be approximated with virtual point lights (VPLs) as well as highly glossy materials. The algorithm extends the Multidimensional Lightcuts technique by effectively creating an illumination-aware clustering of the...

Over the past several decades there has been steady progress towards the goal of polynomial-time approximation schemes (PTAS) for fundamental geometric combinatorial optimization problems. A foremost example is the geometric hitting set problem: given a set P of points and a set D{script} of geometric objects, compute the minimum-sized subset of P...

The geometric hitting set problem is one of the basic geometric combinatorial optimization problems: given a set $P$ of points, and a set $\mathcal{D}$ of geometric objects in the plane, the goal is to compute a small-sized subset of $P$ that hits all objects in $\mathcal{D}$. In 1994, Bronniman and Goodrich made an important connection of this pro...

The geometric hitting set problem is one of the basic geometric combinatorial optimization problems: given a set P of points, and a set \(\mathcal{D}\) of geometric objects in the plane, the goal is to compute a small-sized subset of P that hits all objects in \(\mathcal{D}\). In 1994, Bronniman and Goodrich [6] made an important connection of this...

This study was carried out to detect the effect of water stress on vegetative growth and peroxidase activity of two fig cultivars grown in new reclaimed land, in Egypt. In order to simulate drought circumstances, two irrigation regimes were used to treat fig plants (Ficus carica, L.) as well as a control treatment, i.e. 100% from class A pan (contr...

Weighted geometric set-cover problems arise naturally in several geometric and nongeometric settings (e.g., the breakthrough of Bansal and Pruhs [Proceedings of FOCS, 2010, pp. 407-414] reduces a wide class of machine scheduling problems to weighted geometric set cover). More than two decades of research has succeeded in settling the (1 + epsilon)-...

Weighted geometric set-cover problems arise naturally in several geometric and non-geometric settings (e.g. The breakthrough of Bansal and Pruhs (FOCS 2010) reduces a wide class of machine scheduling problems to weighted geometric set-cover). More than two decades of research has succeeded in settling the (1+ε)-approximability status for most geome...

The present study was conducted during the two growing seasons of 2011 and 2012 to study the effect of different irrigation treatments (100% ETc, 75% ETc and 50% ETc) on some vegetative growth parameters as well as total and relative water contents and leaf chlorophyll content of one-year-old plants. Four fig (Ficus carica L.) cultivars namely; Sul...

The existence of Macbeath regions is a classical theorem in convex geometry ("A Theorem on nonhomogeneous lattices", Annals of Math, 1952). We refer the reader to the survey of I. Barany for several applications [3]. Recently there have been some striking applications of Macbeath regions in discrete and computational geometry. In this paper, we stu...

Geometric set-cover problems arise naturally in several basic settings, and therefore the problem of computing small set covers has been studied extensively. However, after more than two decades of research, $(1+\epsilon)$-approximation algorithms for basic scenarios are still lacking. A prominent example is of weighted disks in the plane for which...

The common fig (Ficus carica L.) trees are one of the earliest cultivated fruit-bearing trees. It is a moderately important world crop, with an estimated annual fruit production of 1,027,194. The aim of the study was to select the most efficient markers to propose a molecular key for seven fig cultivars identification. Genetic similarity matrix was...

Shoot tips of two fig cultivars (Conadria and Black Mission) proliferated in vitro, were cultured on modified MS medium supplemented with 0.5 mg/l 6-benzylaminopurine (BAP). The present investigation aimed to investigate the effect of different medium salt strengths (Double, full, half and quarter) and different sources of carbon (sucrose and fruct...

This work aimed to study the effect of different strengths of Murashig and skoog (MS) medium and carbon sources on in vitro multiplication of two fig cultivars i.e. Sultany and Aboudi. For this purpose, double, full, half and quarter strengths of MS medium and different concentrations of both of sucrose and fructose as carbon source were investigat...

Shoot tips were excised from offshoots of superior male date palm and in vitro cultured on Muarshige and Skoog (MS) medium. Different antioxidant substances (vitamin E, ascorbic and citric acids) with different concentrations were tested on shoot tips browning, swelling and callus induction. In addition, cold pretreatment at 5°C for three or five d...

Shoot tips were excised from offshoots of superior male date palm and in vitro cultured on Muarshige and Skoog (MS) medium. Different antioxidant substances (vitamin E, ascorbic and citric acids) with different concentrations were tested on shoot tips browning, swelling and callus induction. In addition, cold pretreatment at 5°C for three or five d...

Given a set P of n points in the plane, the Oja depth of a point x∈R2x∈R2 is defined to be the sum of the areas of all triangles defined by x and two points from P, normalized with respect to the area of the convex hull of P. The Oja depth of P is the minimum Oja depth of any point in R2R2. The Oja depth conjecture states that any set P of n points...

The present study included anatomical studies of the stems and leaves of 7 cultivars of Ficus carica were investigated. The anatomical examination of the cross sections of the above mentioned stems and leaves revealed diagnostic characters among species. Data of comparative characters reached 14 couplet characters and 2 quantitative characters, dat...

Ficus carica L., well adapted to the Mediterranean climate, is ubiquitous in Egypt. In spite of the large possibilities of its adaptation to the Egyptian climate, its cultivation remains traditional. In Egypt, these species is represented by a large number of varieties which are facing genetic erosion. To save these genetic resources some of the Eg...

The present study included anatomical studies of the stems and leaves of 7 cultivars of Ficus carica were investigated. The anatomical examination of the cross sections of the above mentioned stems and leaves revealed diagnostic characters among species. Data of comparative characters reached 14 couplet characters and 2 quantitative characters, dat...

Uniform shoot tip explants of different fig cultivars i.e Sultany, Aboudi and White Adcy were cultured on Musrashige and Skoog, 1962 (MS medium). Different growth regulators (benzyladenine (BA), isopentenyladenine (2iP), kinetin (Kin) and adenine sulphate (ADS) at 2.5 mg/L were concerned. Many subcultures (first, second and third) were done regular...

Ficus carica L., well adapted to the Mediterranean climate, is ubiquitous in Egypt. In spite of the large possibilities of its adaptation to the Egyptian climate, its cultivation remains traditional. In Egypt, these species is represented by a large number of varieties which are facing genetic erosion. To save these genetic resources some of the Eg...

The colorful Carathéodory theorem [B82] states that given d+1 sets of points in Rd, the convex hull of each containing the origin, there exists a simplex (called a 'rainbow simplex') with at most one point from each point set, which also contains the origin. Equivalently, either there is a hyperplane separating one of these d+1 sets of points from...

This study was conducted on "Maraky" olive seedlings grown at the greenhouse of National Research Center, Dokki, Giza governorate, Egypt. This investigation was performed to study the effect of applying N: P: K (20:20:20) applications as the following (50g in soil 50g spray, 37.5g in soil" 12.5g foliar, 25g in soil + 25g foliar and 12.5g in soil +...

Over the past several decades, many combinatorial measures have been devised for capturing the statistical data depth of a set of n points in ℝ2. These include Tukey depth [15], Oja depth [12], Simplicial depth [10] and several others. Recently Fox et al. [7] have defined the Ray-Shooting depth of a point set, and given a topological proof for the...

We consider the problem of computing minimum geometric hitting sets in which, given a set of geometric objects and a set of points, the goal is to compute the smallest subset of points that hit all geometric objects. The problem is known to be strongly NP-hard even for simple geometric objects like unit disks in the plane. Therefore, unless P=NP, i...

The so-called first selection lemma states the following: given any set P of n points in ℝ d , there exists a point in ℝ d contained in at least c d n d+1−O(n d ) simplices spanned by P, where the constant c d depends on d. We present improved bounds on the first selection lemma in ℝ3. In particular, we prove that c 3≥0.00227, improving the pr...

Given a set P of n points in RdRd and ϵ>0ϵ>0, we consider the problem of constructing weak ϵ-nets for P. We show the following: pick a random sample Q of size O(1/ϵlog(1/ϵ))O(1/ϵlog(1/ϵ)) from P. Then, with constant probability, a weak ϵ-net of P can be constructed from only the points of Q. This shows that weak ϵ-nets in RdRd can be computed from...

Using a technique that Tverberg and Vrecica (TV93) discovered to give a surprisingly simple proof of Tverberg's theorem, we show the following extension of the centerpoint theorem. Given any setP of n points in the plane, and a parameter 1=3 c 1, one can always find a disk D such that any closed half-space containingD contains at leastcn points ofP...

We present new bounds on the first selection lemma in ℜ3. This makes progress on the open problems of Bukh, Matouaek and Nivash [6] and Boros-Füredi [4] for the three-dimensional case, improving the previously best result of Wagner [8]. While our results narrow the gap between the current best lower and upper bounds, they do not settle this questio...

Given a set P of n points in R-d and epsilon > 0, we consider the problem of constructing weak E-nets for P. We show the following: pick a random sample Q of size O(1/epsilon log(1/epsilon)) from P. Then, with constant probability, a weak epsilon-net of P can be constructed from only the points of Q. This shows that weak epsilon-nets in R-d can be...

We prove an optimal extension of the centerpoint theorem: given a set P of n points in the plane, there exist two points (not necessarily among input points) that hit all convex sets containing more than 4 7 n points of P. We further prove that this bound is tight. We get this bound as part of a more general procedure for finding small number of po...

We consider the problem of computing minimum geometric hitting sets in which, given a set of geometric objects and a set of points, the goal is to compute the smallest subset of points that hit a ll geo- metric objects. The problem is known to be strongly NP-hard even for simple geometric objects like unit disks in the plane. Therefore, unless P=NP...

Given a set P of n points in R^d and @e>0, we consider the problem of constructing weak @e-nets for P. We show the following: pick a random sample Q of size O(1/@elog(1/@e)) from P. Then, with constant probability, a weak @e-net of P can be constructed from only the points of Q. This shows that weak @e-nets in R^d can be computed from a subset of P...

Given a set P of n points in Rd and > 0, we consider the problemof constructing weak -nets for P.We show the following: pick a random sample Q of size O(1/ log (1/)) from P. Then, with constant probability, a weak -net of P can be constructed from only the points of Q. This shows that weak -nets in Rd can be computed from a subset of P of size O(1/...

We prove an optimal generalization of the centerpoint theorem: given a set P of n points in the plane, there exist two points (not necessarily among input points) that hit all convex objects containing more than 4n/7 points of P. We further prove that this bound is tight. We get this bound as part of a more general procedure for finding small numbe...

The notion of 'depth' has been used in statistics as a way to iden-tify the center of the bivariate distribution given by the point set P in R 2 . We present a general framework for computing such statistical estimators, that makes extensive use of modern graphics architectures. As a result, we de-rive improved algorithms for a number of depth meas...

Abstract In this paper, we present an algorithm that performs simplification of large geographical maps through a novel use of graphics hardware. Given a map as a collection of non-intersecting chains and a tolerance parameter for each chain, we produce a simplified map that resembles the original map, satisfying the condition that the distance bet...

Given the range space (\(P,\mathcal{R}\)), where P is a set of n points in ℝ2 and \(\mathcal{R}\) is the family of subsets of P induced by all axis-parallel rectangles, the conflict-free coloring problem asks for a coloring of P with the minimum number of colors such that (\(P,\mathcal{R}\)) is conflict-free. We study the following question: Given...

In the Euclidean group Traveling Salesman Problem (TSP), we are given a set of points P in the plane and a set of m connected re- gions, each containing at least one point of P. We want to find a tour of minimum length that visits at least one point in each region. This unifies the TSP with Neighborhoods and the Group Steiner Tree problem. We give...

We consider the problem of approximating a polygonal curve P under a given error criterion by another polygonal curve P’ whose vertices are a subset of the vertices of P. The goal is to minimize the number of vertices of P’ while ensuring that the error between P’ and P is below a certain threshold. We consider two different error measures: Hausdo...

Drugs and other chemical compounds are often modeled as polygonal shapes, where each vertex represents an atom of the molecule, and covalent bonds between atoms are represented by edges between the corresponding vertices. This polygonal shape derived from a chemical compound is often called its molecular graph, and can be a path, a tree, or in ge...

The intersection graph of a set of geometric objects is defined as a graph G = (S,E) in which there is an edge between two nodes s i , s j ∈ S if s i ∩ s j ≠ ∅. The problem of computing a maximum independent set in the intersection graph of a set of objects is known to be NP-complete for most cases in two and higher dimensions. We present approxima...

In many applications it is desirable to cluster high dimensional data along various subspaces, which we refer to as projective clustering. We propose a new objective function for projective clustering, taking into account the inherent trade-off between the dimension of a subspace and the induced clustering error. We then present an extension of the...

We study the following rather generic communication/coordination/computation problem: In a finite network of agents, each initially having one of the two possible states, can the majority initial state be computed and agreed upon by means of local computation only? We study an iterative synchronous application of the local majority rule and describ...

The intersection graph of a set of geometric objects is defined as a graph G (S, E) in which there is an edge between two nodes s(i), s(j) is an element of S if s(i) boolean AND s(j) not equal 0. The problem of computing a maximum independent set in the intersection graph of a set of objects is known to be NP-complete for most cases in two and high...

In this paper we propose algorithms for solving a variety of geometric optimization problems on a stream of points in 2 or 3. These problems include various extent measures (e.g. diameter, width, smallest enclosing disk), collision detection (penetration depth and distance be- tween polytopes), and shape fitting (minimum width annulus, circle/line...

Abstract Drugs and other chemical compounds are often modeled as polygonal shapes, where each vertex represents an atom of the molecule, and covalent bonds between atoms are represented by edges between the corresponding vertices. This polygonal shape derived from a chemical compound is often called its molecular graph, and can be a path, a tree, o...

We consider the problem of approximating a polygonal curve P under a given error criterion by another polygonal curve P’ whose vertices are a subset of the vertices of P. The goal is to minimize the number of vertices of P’ while ensuring that the error between P’ and P is below a certain threshold. We consider two fundamentally different error mea...

We study a rather generic communication/coordination/ computation problem: in a finite network of agents, each initially having one of the two possible states, can the majority initial state be computed and agreed upon by means of local computation only? We describe the architecture of networks that are always capable of reaching the consensus on t...

In this paper, we present an algorithm and a system to perform dynamic view dependent simplification of large geographical maps through a novel use of graphics hardware. Given a map as a collection of non-intersecting chains and a tolerance parameter for each chain, we produce a simplified map that resembles the original map, satisfying the conditi...

In this paper we study a rather generic communication/ coordination/ computation problem: in a finite network of agents, each initially having one of the two possible states, can the majority initial state be computed and agreed upon (i.e., can a democratic consensus be reached) by means of iterative application of the local majority rule. We show...

Given a set P of n points in Rd and �> 0, we consider the problem of constructing weak � -nets for P. We show the following: pick a random sample Q of size O(1/� log(1/� )) from P. Then, with constant probability, a weak � -net of P can be constructed from only the points of Q. This shows that weak � -nets in Rd can be computed from a subset of P o...

This study was conducted on Picual olive seedlings grown at the greenhouse of National Research Center, Dokki, Giza governorate, Egypt. This investigation was performed to study the effect of applying crystalon (20: 20: 20 NPK) at four rates (0, 25, 37.5 and 50% g N/year/plant) as soil application twice monthly (from March till October) parallel wi...